INTERSTATE COUNCIL FOR STANDARDIZATION, METROLOGY AND CERTIFICATION

INTERSTATE

STANDARD

Official publication

SSH1LCHNM!fP[M

GOST 10157-2016

Preface

The goals, basic principles and procedure for carrying out work on interstate standardization are established in GOST 1.0-2015 “Interstate standardization system. Basic provisions" and GOST 1.2-2015 "Interstate standardization system. Interstate standards, rules and recommendations for interstate standardization. Rules for development, acceptance, updating and cancellation"

Standard information

1 DEVELOPED by the Federal State Unitary Enterprise “All-Russian Research Institute for Standardization of Materials and Technologies” (FSUE “VNII SMT”)

2 INTRODUCED by the Interstate Technical Committee for Standardization MTK 527 “Chemistry”

3 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (protocol dated June 28, 2016 No. 49)

4 By Order of the Federal Agency for Technical Regulation and Metrology dated October 26, 2016 No. 1520-st, the interstate standard GOST 10157-2016 was put into effect as a national standard of the Russian Federation on July 1, 2017.

5 INSTEAD GOST 10157-79

Information about changes to this standard is published in the annual information index “National Standards”, and the text of changes and amendments is published in the monthly information index “National Standards”. In case of revision (replacement) or cancellation of this standard, the corresponding notice will be published in the monthly information index “National Standards”. Relevant information, notices and texts are also posted on the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet (wvm.gosi.fu)

In the Russian Federation, this standard cannot be reproduced in whole or in part. replicated and distributed as an official publication without permission from the Federal Agency for Technical Regulation and Metrology

GOST 10157-2016

1 area of use............................................... ...................1

3 Technical requirements................................................... ................2

4 Safety requirements................................................... ...............3

5 Acceptance rules......................................................... ......................4

6 Methods of analysis................................................... .......................4

7 Transportation and storage................................................................... ..........12

8 Manufacturer's warranty................................................................... ................12

Appendix A (informative) Calculation of the amount of gaseous and liquid argon.................................13

Appendix B (for reference) The value of the coefficient K? to bring the volume of gas to normal conditions.................................................... ....................15

method........................................................ ...............16

Gaeochromatographic methods....................................................17

Bibliography................................................. ....................21

GOST 10157-2016

INTERSTATE STANDARD

ARGON GAS AND LIQUID Technical specifications

Gaseous and liquid argon. Specifications

Date of introduction - 2017-07-01

1 area of use

This standard applies to gaseous and liquid argon obtained from air and residual gases of ammonia production and intended for use as a protective medium when welding, cutting and melting active and rare metals and alloys based on them, aluminum, aluminum and magnesium alloys, stainless chromium-nickel heat-resistant alloys and alloy steels of various grades, as well as during the refining of metals in metallurgy. In accordance with the Technical Regulations of the Customs Union 029/2012, argon is a food additive. Used in the food industry as a propellant and packaging gas.

Formula Ag.

Atomic mass (according to international atomic masses 2016) - 39.95.

8 of this standard uses regulatory references to the following interstate standards:

GOST 61-75 Reagents. Acetic acid. Specifications

GOST 427-75 Metal measuring rulers. Specifications

GOST 617-2006 Copper and brass pipes of round section for general purposes. Technical

GOST 949-73 Steel cylinders of small and medium volume for gases at Р р s 19.6 MPa (200 kgf/cm 2). Specifications

GOST 1770-74 (IS01042-83. ISO 4788-80) Laboratory glassware. Cylinders, beakers, flasks, test tubes. General technical conditions

GOST 3022-80 Technical hydrogen. Specifications

Reagents. Ammonia aqueous. Specifications Reagents. Ammonium chloride. Technical specifications Technical silica gel. Specifications Reagents. Nickel (II) nitrate 6-water. Specifications Reagents. Barium hydroxide 8-water. Specifications Reagents. Barium chloride 2-water. Specifications Reagents. Copper(I) chloride. Specifications Reagents. Copper (II) sulfate 5-water. Specifications Reagents. Potassium iodide. Technical conditions Liquid oxygen, technical and medical. Technical specifications Wire woven sieves with square cells. Technical specifications Distilled water. Specifications (ISO 2435-73) Nitrogen, gaseous and liquid. Specifications

GOST 3760-79 GOST 3773-72 GOST 3956-76 GOST 4055-78 GOST 4107-78 4108-72 4164-79 GOST 4165-78 GOST 4232-74 GOST 6331-78 GOST 6613-86 GOST 6709-72 GOST 9293 -74

Official publication

GOST 10157-2016

GOST 10163-76 Reagents. Soluble starch. Specifications

GOST 10727-2015 Unidirectional glass threads. Specifications

GOST 13320-81 Automatic industrial gas analyzers. General technical conditions

GOST 16539-79 Reagents. Copper (I) oxide. Specifications

GOST 17433-60 Industrial cleanliness. Compressed air. Pollution classes

GOST 18300-87 Rectified technical ethyl alcohol. Specifications*

GOST 22967-90 Medical injection syringes for multiple use. General technical requirements and test methods

GOST 25336-82 Laboratory glassware and equipment. Types, main parameters and sizes

GOST 25706-83 Lula. Types, basic parameters. General technical requirements GOST 26460-85 Air separation products. Gases. Cryoproducts. Packaging, labeling, transportation and storage

GOST 27068-86 Reagents. Sodium sulfate (sodium thiosulfate) 5-water. Specifications

GOST 29227-91 (ISO 835-1-81) Laboratory glassware. Graduated pipettes. Part 1. General requirements

GOST 29251-91 (ISO 365-1-84) Laboratory glassware. Burettes. Part 1. General requirements

Note - When using this standard, it is advisable to check the validity of the reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or using the annual information index “National Standards”, which was published as of January 1 of the current year, and on issues of the monthly information index “National Standards” for the current year. If the reference standard is replaced (changed), then when using this standard you should be guided by the replacement (changed) standard. If the reference standard is canceled without replacement, then the provision in which a reference is made to it is applied in the part that does not affect this reference.

3 Technical requirements

3.1 Gaseous and liquid argon must be manufactured in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner.

3.2 Characteristics

3.2.1 In terms of physical and chemical parameters, gaseous and liquid argon must comply with the standards specified in Table 1.

Table 1

3.2.2 The volume fraction of the sum of carbon-containing compounds is not standardized in gaseous and liquid argon produced from air if an electronic

* Lost force on the territory of the Russian Federation from September 1, 2014. GOST R 55676-2013 is in force.

GOST 10157-2016

hydrogen that does not contain impurities of carbon-containing compounds and alkali, as well as hydrogen from coke oven gas and synthesis gas, specially purified in ammonia production.

3.2.3 The standards for liquid argon indicated in Table 1 correspond to the indicators of gaseous argon obtained by complete evaporation of a sample of liquid argon.

3.2.4 It is allowed to reduce the amount of liquid argon due to its evaporation during transportation and storage by no more than 10%.

3.3 Marking

3.3.1 Marking of gaseous and liquid argon - according to GOST 26460.

3.3.2 Marking characterizing the danger of argon gas: name of the cargo “COMPRESSED ARGON”, hazard class 2. classification code 2211. danger sign number - 2.2. UN number 1006. emergency card 201. classification code 1A. danger code 20.

3.3.3 Marking characterizing the danger of liquid argon: name of the cargo “COOLED LIQUID ARGON”, hazard class 2. classification code 2213. danger sign number - 2.2, UN number 1951. emergency card 201. classification code FOR. danger code 22.

3.4 Packaging

Packaging of gaseous and liquid argon - according to GOST 26460.

4 Safety requirements

4.1 Argon is non-toxic and non-flammable. however, it poses a danger to life: when inhaled, a person instantly loses consciousness, and death occurs within a few minutes. The narcotic effect of inhaling argon appears only at barometric pressure above 0.2 MPa. High concentrations of argon in the inhaled air can cause dizziness and nausea. vomiting, loss of consciousness and death from asphyxia (as a result of oxygen starvation). 8 a mixture of argon with other gases or a mixture of argon with oxygen with a volume fraction of oxygen in the mixture of less than 19%, oxygen deficiency develops, and with a significant decrease in the oxygen content - suffocation.

4.2 Argon gas is heavier than air and can accumulate in poorly ventilated areas near the floor and in pits, as well as in the internal volumes of equipment intended for production. storage and transportation of gaseous and liquid argon. At the same time, the oxygen content in the air decreases, which leads to oxygen deficiency, and with a significant decrease in oxygen content - to suffocation, loss of consciousness and death of a person.

4.3 In 8 places where argon gas may accumulate, it is necessary to monitor the oxygen content in the air using automatic or manual devices with a device for remote air sampling. The volume fraction of oxygen in the air must be at least 19%.

4.4 Liquid argon is a low-boiling liquid that can cause frostbite to the skin and damage to the mucous membrane of the eyes. When sampling and analyzing liquid argon, it is necessary to wear safety glasses.

4.5 Before carrying out repair work or examining a previously used transport or stationary container of liquid argon, it must be warmed to ambient temperature and purged with air. It is allowed to start work when the volume fraction of oxygen inside the container is at least 19%.

4.6 When working in an argon atmosphere, it is necessary to use insulating oxygen devices or a hose gas mask.

4.7 The operation of cylinders filled with argon gas must be carried out in accordance with regulations establishing the rules for the design and safe operation of pressure vessels*.

* On the territory of the Russian Federation, Rostechnadzor order dated March 25, 2014 N9 116 “On approval of Federal norms and rules in the field of industrial safety “Rules for industrial safety of hazardous production facilities that use equipment operating under excess pressure” is in force (registered with the Ministry of Justice of Russia on May 19. 2014 No. 32326).

GOST 10157-2016

5 Acceptance rules

5.1 Gaseous and liquid argon are taken in batches. A batch is considered to be any quantity of a product. homogeneous in quality indicators and documented in one quality document.

Each batch of liquid and gaseous argon must be accompanied by a quality document containing the following data:

Name of the manufacturer and its trademark;

Name of the product, its grade;

Date of manufacture;

Batch number;

Volume of argon gas in cubic meters and mass of liquid argon in tons or kilograms (see Appendix A):

Results of analyzes performed or confirmation of product compliance with the requirements of this standard;

Designation of this standard;

A type of hydrogen used to purify raw argon.

5.2 To determine the volume fraction of oxygen and the volume fraction of water vapor, one cylinder is selected from the total number of cylinders simultaneously filled with argon from a common pipeline on one or more filling manifolds; to determine the volume fraction of nitrogen, two cylinders are selected from those simultaneously filled on each filling manifold.

If unsatisfactory results of the analysis are obtained for at least one indicator, a repeated analysis is carried out on it on a double sample. The results of the re-analysis apply to all simultaneously filled cylinders.

The volume fraction of the sum of carbon-containing compounds is determined in samples taken every 8 hours from the common pipeline of argon gas supplied to the collectors. If unsatisfactory analysis results are obtained, repeat analyzes are carried out, selected from 2% of the cylinders. filled within 8 hours. The results of repeated analyzes apply to all cylinders filled during the specified period of time.

To control the argon pressure in filled cylinders, 10% of the cylinders of replacement production are selected.

5.3 To control the quality of argon gas by the consumer, 10% of the cylinders of the batch are selected, but not less than two cylinders for a batch of less than 20 cylinders. The pressure in selected cylinders is checked.

5.4 To control the quality of argon gas transported in auto-recipients, a sample is taken from each auto-recipient.

5.5 To control the quality of liquid argon, a sample is taken from each transport tank. The manufacturer is allowed to take a sample of liquid argon from a stationary container before filling tankers.

If unsatisfactory results of the analysis according to 5.3-5.5 are obtained for at least one of the indicators, a repeated analysis is carried out on it on a double sample. The results of the re-analysis apply to the entire batch.

6 Methods of analysis

6.1 General instructions

General instructions for conducting analysis - according to GOST 27025.

It is allowed to use other measuring instruments with metrological characteristics and equipment with technical characteristics no worse, as well as reagents of quality no lower than those specified in this standard.

It is allowed to use other methods of analysis that ensure the required accuracy and reliability of the determination results. The methods used must be certified in accordance with the established procedure.

In case of disagreement in assessing the quality of the product, the analysis is carried out using the methods specified in this standard.

GOST 10157-2016

The results of the determination are rounded to the number of significant figures to which the norm for this indicator corresponds.

By agreement with the consumer, it is allowed to round the determination results to the number of significant figures established by the requirements of the agreement (contract).

All measuring instruments used must be verified and testing equipment must be certified.

6.2 Sampling

6.2.1 A sample of argon gas is taken from a filled cylinder at a pressure not lower than (14.7 ± 0.5) MPa 1(150 ± 5) kgf/cm2) or (19.6 ± 1.0) MPa ((200 ±10) kgf/cm2 ) and temperatures from 15 *C to 30 *C. directly into the analysis device using a reducer or fine adjustment valve and a steel or copper connecting tube from the sampling point to the device. The reducer or valve is flushed with the analyzed gas by raising the pressure twice to 0.98 MPa (10 kgf/cm2) and releasing the pressure: the connecting tube is purged with at least ten times the volume of the analyzed gas. When determining the volume fraction of water vapor, a sample is taken through a stainless steel tube.

6.2.2 A sample of liquid argon is taken into the installation (Figure 1). the main parts of which are: a cryogenic vessel SK-6, designed for a pressure of 0.03 MPa (0.3 kgf/cm2), with a lid equipped with two tubes, one of which reaches the bottom of the vessel, the second is short, closed with a clamp, and a coil evaporator from pipes DKRNM 3 x 0.5 ND M3 according to GOST 617. length 500 mm.

X - rubber tube with clamp; 2 - copper tube in - 1; 3 - cover. L - rubber tube; S - coil evaporator. c - a vessel with water. 7 - cryogenic vessel, c - stainless steel tube 3"0.7; d - gasket

Figure 1 - Installation for the selection of liquid argon

Before taking a sample of liquid argon, the cryogenic vessel is cooled by pouring 50-100 cm 3 of the analyzed liquid argon. The remaining liquid that has not evaporated is poured out of the vessel and a sample of liquid argon is immediately poured into it, filling the vessel by approximately */2 volume.

With clamp 1 open, close the cryogenic vessel with a lid and attach to it a coil evaporator, an immersed vessel with water heated to a temperature of 50°C - 60°C. A short tube is connected to a balpon with premium argon gas through a pressure reducing valve, which regulates the rate of flow of liquid argon into the evaporator.

It is allowed to take a sample of liquid argon directly into the device for analysis through an emee-vik evaporator. In this case, a snake evaporator, immersed in a vessel with water, is connected to the valve of a container with liquid argon using a stainless steel tube with an internal diameter of 1.5-2.5 mm.

GOST 10157-2016

6.3 Determination of the volume fraction of argon

6.3.1 Volume fraction of argon X.%. calculated by the formula

X = 100 - (X, + X 2 * X e + X 4), (1)

where X is the volume fraction of oxygen. %;

X 2 - volume fraction of nitrogen. %;

Xe is the volume fraction of water vapor. %;

X 4 - volume fraction of the sum of carbon-containing compounds in terms of CO g.%.

6.4 Determination of oxygen volume fraction

6.4.1 Equipment, reagents and solutions Flask Kn-1-100*29/32 according to GOST 25336.

Pipettes with a capacity of 2.10 and 25 cm 3 according to GOST 29227.

Burettes with a capacity of 1 and 5 cm 3 according to GOST 29251.

The installation for oxygen determination consists of an analysis vessel (Figure 2). bottles for absorption solution with a capacity of 5-10 dm 3 with a drain tube (siphon) and test tubes for colorimetry (Figure 3).

The analysis vessel of type SV-7631 M3 has two volumes - A and B. separated by a two-way valve 2 equipped with an extension for connecting to the sampling site, and valve 1 for introducing the absorption solution into the vessel. The capacity of volume A is about 5 dm 3, volume B is about 25 cm 3.

I “- connection of vessel A with the atmosphere. II - the valve is closed; III - connection of vessel A with vessel B; T - one-way valve: ? - two-way valve

Figure 2 - Analysis vessel type SV-7631 M3

GOST 10157-2016

Figure 3 - Test tube for colorimetry

Argon gas according to this standard.

Nitrogen gaseous according to GOST 9293. technical. 1st grade.

Aqueous ammonia according to GOST 3760. solutions with a mass fraction of 25% and 4%.

Ammonium chloride according to GOST 3773.

Distilled water according to GOST 6709.

Potassium iodide according to GOST 4232. solution with a mass fraction of 10%.

Acetic acid according to GOST 61. x. h.. icy.

Soluble starch according to GOST 10163, solution with a mass fraction of 1%.

Sodium sulfate (sodium thiosulfate) 5-water according to GOST 27068. solution of molar concentration with (Na 2 S 2 0 3) = 0.05 mol/dm 3.

Copper (II) sulfate S-aqueous according to GOST 4165. solution of molar concentration with (1/2CuS0 4) = 0.05 mol/dm 3.

Copper (I) chloride according to GOST 4164.

Round copper wire for electrical engineering, type MM. diameter 0.8-2.5 mm. in the form of a spiral.

Crane lubricant.

Copper monochloride ammonia solution (absorption solution); prepared at the rate of 12 g of copper monochloride, 36 g of ammonium chloride. 145 cm 3 of ammonia solution with a mass fraction of 25% per 1 dm 3 of water. The solution is prepared in a bottle filled with copper wire spirals. Water and an ammonia solution are poured into the bottle, then weighed amounts of ammonium chloride and copper chloride are added. The solution is purged with argon until the salts are completely dissolved and the solution becomes discolored, after which it is protected from air access.

GOST 10157-2016

A solution of copper sulfate with a molar concentration of (1/2 CuS0 4) = 0.05 mol/dm 3 is prepared as follows: 12.484 g of freshly recrystallized copper sulfate is dissolved in water in a flask with a capacity of 1 dm 3. The titer of the solution is determined by the iodometric method.

Iodine. released by adding 10 cm 3 of potassium iodide solution and 2-3 cm 3 of acetic acid to 25 cm 3 of the analyzed solution, titrate with a solution of sodium thiosulfate in the presence of starch until the solution becomes discolored. The correction factor (K,) for a solution of copper sulfate is calculated as the quotient of the volume of sodium sulfate solution used for titration divided by 25.

Sample solutions are prepared in test tubes for colorimetry. into each of which a solution of copper sulfate is poured in the quantities indicated in Table 2, and then the volume of the solution is adjusted to 25 cm 3 with an ammonia solution with a mass addition of 4%.

Shelf life of sample solutions is 6 months.

table 2

Sample solution number	The volume of copper sulfate solution with a molar concentration of exactly 0.05 mol/dm 3, si 3	Volume of oxygen a sample corresponding to the color of the solution, cm 3










Note - The volume of oxygen equivalent to 1 cm 3 solution of copper sulfate molar con-. 0.05 11200 293 n „ nrt „ concentration 0.05 mol/dm 3 . equal to -- ------ = 0.300 cm 3 at 20 *C and 101.3 kLa (760 mm Hg). If con- the concentration of the copper sulfate solution is not exactly 0.05 mol/dm 3, then the values given in column 3 are multiplied by the coefficient K,.

6.4.2 Conducting analysis

Before analysis, the vessel is washed with a chromium mixture, then with water and dried in a stream of nitrogen.

Open taps 1 and 2 (see Figure 2) and attach the analysis vessel to the sampling site. Purge the vessel with at least ten times the volume of the gas being analyzed. Having reduced the gas flow, close valve 1, then valve 2 and disconnect the device from the sampling site. The gas pressure in the device is equalized with atmospheric pressure by quickly turning tap 2, the tip of which is first immersed in the lead. Barometric pressure and ambient temperature are noted.

Fill volume B through tap 1 with the absorption solution, having previously drained the first portion of the solution from the siphon.

Tap 1 is closed and a sample solution is selected that matches the color of the solution in volume B.

Opening tap 2 (with tap 1 closed), pour in the absorption solution in volume A and vigorously shake the vessel until the solution completely absorbs oxygen from the gas being analyzed.

Return the solution to volume B and select a sample solution that matches the color of the solution in volume B.

GOST 10157-2016

6.4.3 Processing results

The volume fraction of oxygen X, %, is calculated using the formula

x (U a -C) 100

where V is the volume of the gas sample, equal to the capacity of the volume A. cm 3;

V, is the volume of oxygen corresponding to the selected reference solution before oxygen absorption. cm e;

V 2 is the volume of oxygen corresponding to the selected reference solution after oxygen absorption, cm 3 ;

K 2 - coefficient for bringing the volume of dry gas to a temperature of 20 °C and 101.3 kLa (760 mmHg) is determined from the table given in Appendix B.

The result of the analysis is taken to be the arithmetic mean of the results of two parallel determinations, the relative discrepancy between which does not exceed the permissible discrepancy. equal to 15%.

The permissible relative total error of the analysis result is ± 30% with a confidence level of P = 0.95.

The volume fraction of oxygen can be determined using multi-scale instruments with a galvanic cell with a solid electrolyte (in this case, the volume fraction of hydrogen and flammable impurities should not exceed 1% of the measured volume fraction of oxygen), as well as from the filling pipeline with industrial automatic gas analyzers of continuous action according to GOST 13320 with relative accuracy not less than 10%. for example, type GL.

In case of disagreement in the assessment of the volume fraction of oxygen, the analysis is carried out using the colorimetric method using a copper chloride solution according to 6.4.2.

6.5 Determination of the volume fraction of nitrogen

6.5.1 Hardware

Spectral gas analyzers of various types with a relative error of no more than 15%.

Test gas mixtures with a volume fraction of nitrogen in argon of 5 ppm - GSO No. 3992-87.10 ppm - GSO No. 3994-87.20 ppm - GSO No. 3995-87.50 ppm - GSO No. 3997-87.90 ppm - GSO No. 3994-87 no State Register.

6.5.2 Conducting analysis

The operating principle of the gas analyzer is based on measuring the radiation intensity of the molecular band of nitrogen excited by an electric discharge in the analyzed gas.

Preparation for analysis and its implementation are carried out in accordance with the operating instructions for the device.

6.5.3 Processing results

Volume fraction of nitrogen X 2. %. determined in accordance with the steady-state readings of the device.

The volume fraction of nitrogen can be determined by gas adsorption chromatographic method using a chromatograph with a highly sensitive thermal conductivity detector with a threshold sensitivity for nitrogen of no more than 5 ppm.

The volume fraction of nitrogen in argon can be determined by other instruments with a relative error of no more than 15%.

In case of disagreement in the assessment of the volume fraction of nitrogen, the analysis is carried out using the spectral method.

6.6 Determination of the volume fraction of water vapor

6.6.1 Hardware

coulometric gas moisture meters, designed to measure microconcentrations of water vapor, with a relative measurement error of no more than 10% at concentrations from 0 to 20 ppm and no more than 5% at higher concentrations.

6.6.2 Conducting analysis

The coulometric method is based on the continuous quantitative extraction of water vapor from the test gas by a hygroscopic substance and the simultaneous electrolytic decomposition of

GOST 10157-2016

baked water into hydrogen and oxygen, while the electrolysis current is a measure of the concentration of water lars.

The device is connected to the sampling site with a stainless steel tube. The gas flow rate is set to (50 ± 1) cm 3 /min. The measuring range switch is set as follows. so that the instrument readings are within the second third of the measuring scale, graduated in parts per million (ppm). The electrolysis current is measured with a microammeter.

The temperature of the cylinder with the analyzed gas must not be lower than 15 * C. The analysis is carried out according to the instructions supplied with the device.

6.6.3 Processing results

Volume fraction of water vapor X y ppm. determined in accordance with the established readings of the device.

It is allowed to determine the volume fraction of water vapor by the condensation method given in Appendix B.

In case of disagreement in the assessment of the volume fraction of water vapor, the analysis is carried out using the coulometric method.

6.7 Determination of the volume fraction of the amount of carbon-containing compounds in terms of CO 2

6.7.1 Apparatus, reagents and solutions

Analysis setup (Figure 4). consists of an electric furnace designed to heat up to a temperature of 900 * C, a quartz tube with an internal diameter of 25 to 30 mm. filled with copper oxide, an absorber (Figure 5) and a gas drum meter with a liquid seal of the RG-700 type.

Burettes with a capacity of 25 and 50 cm 3 with a division price of 0.1 cm 3 according to GOST 29251.

Pipettes with a capacity of 20 cm 3 according to GOST 29227.

Flask 1-1000-2 according to GOST 1770.

Non-automatic scales with a maximum weighing limit of 200 g and an error of ± 0.2 mg.

Mechanical stopwatch.

Argon gas, additionally purified from carbon dioxide, using an alkaline absorber of any type or low-temperature adsorption to a residual volume fraction of no more than 5-10" 5%.

Distilled water according to GOST 6709. Freshly boiled.

1 - electric furnace: 2 - ceramic tube: 3 - copper oxide: 4 - absorber: 5 - gas drum meter

Figure 4 - Analysis setup

GOST 10157-2016

f - five full eitsoa tpy6iH with a diameter of (6 t 1) mm, 2 - glass lintel. 3 - place of the scarlet line

Figure 5 - Absorber

Barium chloride according to GOST 4108.

Hydrochloric acid, solution of molar concentration with (HCI) = 0.01 mol/dm 3 (0.01 k); prepared from fixanal hydrochloric acid.

Copper (II) oxide according to GOST 16539.

Rectified technical ethyl alcohol, premium grade, according to GOST 18300. solution with a mass fraction of 60%.

Phenolphthalein, alcohol solution with a mass fraction of 0.1%.

Barium hydroxide 8-water according to GOST 4107. solution of molar concentration with (1/2 Ba(OH) 2) = 0.01 mol/dm 3 ; prepared as follows: 1.8 g of Ba(0H) 2 -8H 2 0 and 0.35 g of 8aC1 2 -2H 2 0 are dissolved in 200-300 cm 3 of hot water in a volumetric flask with a capacity of 1000 cm 3, the cooled solution is brought to the mark with water and filtered into argon current. The solution must be protected from atmospheric air during storage and use.

6.7.2 Conducting analysis

Determine the concentration of barium hydroxide solution (control sample). To do this, 20 cm 3 of solution is taken into an absorber and titrated in a stream of argon, purified from carbon dioxide, with a solution of hydrochloric acid in the presence of 2-3 drops of phenolphthalein solution.

The analyzed argon is passed through a tube with copper oxide heated to a temperature of 800 9 C - 850 ° C. e for 10 minutes at a rate of about 5 dm 3 /h and released into the atmosphere. Then an absorber is connected to the tube, into which 20 cm 3 of barium hydroxide solution is poured and 20 dm 3 of the analyzed argon is passed through the installation, maintaining a gas speed of about 10 dm 3 / h. After this, the solution in the absorber is titrated in a stream of argon, purified from carbon dioxide, with hydrochloric acid in the presence of 2-3 drops of phenolphthalein solution until the solution becomes discolored.

GOST 10157-2016

6.7.3 Processing results

The volume fraction of the sum of carbon-containing compounds in terms of C0 2 X 4,%, is calculated using the formula

0.12(^3 ~U 4)100

H,

where V 3 is the volume of hydrochloric acid solution consumed for titration of the control sample, cm 3 ;

Va is the volume of hydrochloric acid solution consumed for titrating the solution after absorption of carbon dioxide, cm 3 ;

0.12 - coefficient taking into account the equivalent ratio of barium hydroxide solution of molar concentration with (1/2 Ba(OH) 2) = 0.01 mol/dm 3 and carbon dioxide;

V n is the volume of gas taken for analysis, reduced to normal conditions, cm 3.

The permissible relative total error of the analysis result is i 25% with a confidence probability of P - 0.95.

It is allowed to determine the volume fraction of the sum of carbon-containing compounds in terms of C0 2 by gas chromatographic methods given in Appendix D.

In case of disagreement in the assessment of the volume fraction of the sum of carbon-containing compounds in terms of CO2, the analysis is carried out using the titrometric method.

6.8 Volume fractions of oxygen and the amount of carbon-containing compounds in terms of CO 2 can be determined by gas adsorption chromatographic method using a chromatograph with a highly sensitive argon discharge detector with a threshold sensitivity of no higher than 0.5 ppm for each impurity being determined.

7 Transportation and storage

Transportation and storage of gaseous and liquid argon - in accordance with GOST 26460.

The nominal pressure of argon at a temperature of 20 * C during filling, storage and transportation of cylinders and auto-recipients should be (14.7 ± 0.5) MPa [(150 1 5) kgf/cm 2 ] or (19.6 ± 1.0) MPa [(200 ± 10) kgf /cm 2 ].

8 Manufacturer's warranty

8.1 The manufacturer guarantees that the quality of gaseous and liquid argon meets the requirements of this standard provided that the consumer complies with the storage and transportation conditions.

8.2 The guaranteed shelf life of argon gas is 18 months from the date of manufacture.

GOST 10157-2016

Appendix A

(informative)

calculating the amount of gaseous and liquid argon

A.1 Volume of argon gas in the cylinder V„, m3. under normal conditions, calculated by the formula

V„ = KV 6, (A.1)

where K is the coefficient for calculating the volume of gas in the cylinder, given in Table A.1. taking into account the compressibility of argon, pressure and temperature of the gas in the cylinder:

Vg is the average capacity of the cylinder, dm 3.

Table A.1 - Coefficient K for calculating the volume of gas in a cylinder in m 3 under normal conditions of 20 * C and 101.3 kLA (760 mm Hg)

Temperature in the cylinder. "WITH

Excessive gas pressure in the cylinder. MPa (“tsGsm 2)

GOST 10157-2016

The arithmetic mean of capacities of at least 100 cylinders is taken as the statistical average.

293 10~ 273 + 1 Z

where P is the gas pressure in the cylinder, measured by a pressure gauge, kgf/cm 2 ;

0.968 - conversion factor of technical atmospheres (kgf/cm 2) into physical atmospheres: t - gas temperature in the cylinder when measuring pressure. *WITH;

Z is the compressibility coefficient of argon at temperature 1.

For example, when argon gas is supplied in cylinders in accordance with GOST 949 with a capacity of 40 dm 3, the volume of gas in the cylinder is.

at a pressure of 150 kgf/sy 2 at a temperature of 20 * C

0.155-40 = 6.20 m3;

at a pressure of 200 kgf/sy 2 at a temperature of 20 "C

0.206 40 = 8.24 m3.

A.2 The amount of liquid argon in tanks is measured in tons or kilograms.

When converting the mass or volume of liquid argon to m 3 of gaseous argon under normal conditions, use the formulas given below.

|de t - mass of liquid argon, g.

V* - volume of liquid argon, dm 3:

1.662 - density of gaseous argon under normal conditions, kg/m 3: 1.392 - density of liquid argon at normal pressure, kg/dm 3.

GOST 10157-2016

Appendix B

(informative)

The value of coefficient K 2 to bring the volume of gas to normal conditions

Table B.1 - The value of the K 2 coefficient for bringing the volume of gas to standard conditions

Temperature, *С	Barometer readings. "Pa (mmHg)

GOST 10157-2016

Determination of the volume fraction of water vapor by the condensation method

The volume fraction of water vapor is determined by condensation-type devices with a threshold sensitivity of no higher than 1.5 ppm.

The relative error of the device should not exceed 10%.

The method is based on measuring the temperature of gas saturation with water vapor when dew appears on a cooled mirror surface.

The analysis is carried out according to the instructions attached to the device.

The volume fraction of water vapor in accordance with the found saturation temperature is determined according to Table B.1.

Table B.1

Volume fraction of water vapor. ppm	Saturation temperature. 'WITH	Volume fraction of water vapor, ррлч	Saturation temperature. "WITH








Note - Volume fraction equal to 1 ppm. corresponds to 1-10 -4%.

The arithmetic mean of the results of two parallel determinations is taken as the result of the analysis. the relative discrepancy between them does not exceed the permissible discrepancy of 10%.

The permissible relative total error of the analysis result is 125% with a confidence probability of P-0.95.

GOST 10157-2016

Determination of the volume fraction of the sum of carbon-containing compounds by gas chromatographic methods

D.1 Determination of the volume fraction of carbon dioxide obtained from the oxidation of carbon-containing compounds with copper oxide D.1.1 Equipment, materials and reagents

A chromatograph with a thermal conductivity detector with a sensitivity threshold for propane with a carrier gas of helium not higher than 2-1 (7 * mg/cm 3 and ha eochrome with a graphic column 1.4 m long, with an internal diameter of 4 mm, filled with active carbon.

The concentrator is U-shaped. For production, a stainless steel tube measuring 6*1 mm is taken. 500 mm long. The concentrator is filled with crushed laboratory glass. A glass adapter (Figure D. 1) with an extension and a plug for introducing the sample is attached to the concentrate.

Figure D.1 - Glass adapter with plug

The Dewar flask is glass, with a capacity of about 0.5 dm 3.

Gas drum meter (with liquid seal) type RG-700.

Auxiliary equipment for chromatographic analysis:

Measuring magnifier according to GOST 25706 16‘ magnification with a division value of 0.1 mm:

metal ruler according to GOST 427;

a set of sieves with meshes in accordance with GOST 6613 or sieves of a similar type:

medical injection spreads, Record type according to GOST 22967, capacity 2. 5. 10 cm 3: mechanical stopwatch: foam flow meter.

GOST 10157-2016

Liquid technical oxygen according to GOST 6331.

Purified gaseous helium with a volume fraction of carbon dioxide not exceeding 0.0001%.

Test gas mixture with a volume fraction of carbon dioxide in nitrogen of 0.50% - GSO No. 3765-87 according to Gosrevstr.

Active carbon of the SKT brand. fraction with particles 0.2-0.5 mm in size, dried at a temperature of 150 * C for 4 hours.

Laboratory glass crushed in a porcelain mortar. The fraction with particles 0.2-0.5 mm in size is washed with hot distilled water and dried at a temperature of 150 * C for 4 hours.

Copper mesh with a cell size of 0.1-0.15 mm or glass fiber according to GOST 10727.

D.1.2 Preparation for analysis

The gas chromagographic column is filled with active carbon; A layer of glass fiber 8-12 mm thick is laid on top of the coal layer. Then the column is fixed in the chromatograph thermostat and. without connecting to the detector. additionally dried at a temperature of 150 * C for 8 hours in a current of carrier gas at a flow rate of 30 cm 3 /min.

The concentrator is filled with crushed glass; A copper mesh is laid on top of the glass layer. The filled concentrator is purged with carrier gas for 3 hours.

The volume fraction of carbon dioxide is determined by the absolute calibration method, using a calibration gas mixture (hereinafter referred to as SGM).

From 3 to 5 doses of PGS with a volume of 2 to 10 cm 3 are introduced into the chromatograph through a concentrator, which is connected to the chromatograph instead of a replaceable dose with short vacuum tubes.

Before administering each dose, flush the concentrator with carrier gas (helium) for 1 minute. Then, stopping the helium supply, place the concentrator in a Dewar flask with liquid oxygen. After 3 minutes, the supply of carrier gas is turned on and a dose of PGS is introduced into its flow through an adapter. After 1 minute, replace the Dioara vessel with liquid oxygen with a vessel with water heated to 25 * C - 30 * C. and record a chromatogram of the desorbed carbon dioxide.

Based on the PGS chromatograms, a calibration graph of the dependence of the height of the carbon dioxide peak in millimeters was constructed. reduced to the sensitivity of the recorder (scale) M1. from the volume of carbon dioxide in each dose 1L) according to the formula

s", o s,

where C c1 is the volume fraction of carbon dioxide in the ASG. %;

Yes - the dose of PGS. cm 3.

Graduation conditions;

temperature of the geochromatographic column -150 * C;

carrier gas consumption (helium) - 30 cm 3 /min.

The detector supply current and the sensitivity of the recorder are established experimentally, depending on the type of chromatograph.

The calibration is checked once a month using a gas mixture of carbon dioxide and nitrogen with a carbon dioxide volume fraction set at about 0.5%.

D. 1.3 Conducting analysis

The chromatograph is connected to the network and switched to normal mode.

The concentrator is connected to the switching valve of the chromatograph and purged with at least ten times the volume of helium. At the same time, the flow rate of the analyzed gas is set to about 300 cm 3 /min according to the readings of the foam flow meter.

Place the concentrator in a oxygen vessel with liquid oxygen. After 3 minutes, the analyzed gas is directed into the concentrate and 3 to 5 dm 3 of gas is passed through, depending on the measured volume fraction of carbon dioxide. The sample volume is measured using the gas meter readings.

Having finished sampling, flush the cooled concentrator with helium for 1-2 minutes. then replace the Dioara vessel with liquid oxygen with a vessel with water heated to a temperature of 25 * C - 30 "C. and record a chromatogram of desorbed carbon dioxide. The temperature of the gas chromatographic column, the flow rate of the carrier gas (helium) and the supply current of the detector must be identical to those adopted during calibration The range of the recorder scale is selected so that the peak of carbon dioxide is maximum within the chart range of the recorder.

D. 1.4 Processing results

Based on the height of the carbon dioxide peak, reduced to the sensitivity of the M1 recorder. Determine the volume of carbon dioxide in the argon sample using the calibration graph and calculate the volume fraction of carbon dioxide X.%. according to the formula

GOST 10157-2016

where V y is the volume of carbon dioxide in the 8th sample of argon according to the calibration curve, cm 3; V is the volume of argon sample, cm3.

The result of the analysis is taken as the arithmetic mean of two parallel determinations, the permissible differences between which should not exceed 15% relative to the average result of a certain value with a confidence probability of 0.95.

D.2 Determination of the volume fraction of the sum of carbon-containing compounds with preliminary

hydrogenation of carbon monoxide and dioxide

D.2.1 Equipment, materials and reagents

Chromatograph with a flame ionization detector, with a sensitivity threshold for propane not higher than 2.5-10"^ mg/s.

The reactor is a stainless steel tube with a diameter of 3 to 5 mm. 100-300 mm long. filled with catalyst. placed in an oven designed to heat up to a temperature of 500 * C.

Auxiliary equipment for chromatographic analysis according to G.1.1.

Argon gas according to this standard, additionally purified from carbon-containing compounds to a volume fraction of no more than 0.0001%.

Technical hydrogen according to GOST 3022 grade A or B. additionally purified from carbon dioxide-containing compounds to a volume fraction of no more than 0.0001%.

Compressed air according to GOST 17433. pollution class not higher than 2.

Pure gaseous methane with a volume fraction of the main substance of at least 99.6%.

Nickel (II) nitrate 6-iodine according to GOST 4055.

Technical fine-pored silica gel according to GOST 3956. fraction with particle size 0.5-1 mm.

Test gas mixtures with a volume fraction of methane in the air of 2.5 ppm and 7.5 ppm - GSO No. 3696-87; 10 ppm - GSO N? 3897-87 according to the State Register.

Test gas mixture with a volume fraction of carbon dioxide in nitrogen of 50 ppm - GSO No. 3746-87 according to the State Register.

D.2.2 Preparation for analysis

D.2.2.1 Install a gas chromagographic column (no more than 1 m long) in the chromatograph. not filled with adsorbent.

The catalyst for filling the reactor is prepared as follows. Dry the silica gel at a temperature of 150 * C - 180 °C for 4 hours in a drying cabinet, place it in a porcelain cup and fill it with a solution of nickel nitrate at the rate of: per 20 g of silica gel about 10 g of Ni(N0 3) 2 -6H 2 0 dissolved in water. Silica gel must be completely immersed in the solution. The excess solvent is evaporated at a temperature of 600 °C - 800 * C until the release of nitrogen oxides stops, then it is cooled, the reactor is filled, it is connected to the chromatograph and the nickel oxide is reduced to metallic nickel. flow of hydrogen (flow rate 60 cm 3 /min) at a temperature of 400 * C -500 * C for 4 hours.

The activity of the catalyst is checked using a test gas mixture of carbon dioxide in argon.

In a reactor connected via a tee to a gas chromatographic column (at the gas outlet), carbon dioxide is hydrogenated with hydrogen at a temperature of 450 * C - 500 * C to methane. The methane peak is detected by a flame ionization detector. The volume fraction of carbon dioxide is determined from the height of the methane peak and compared with the nominal content of carbon dioxide in the mixture. The permissible discrepancy between the results is no more than 5%.

An additional source of hydrogen is present in two columns, the first of which is filled with anhydrone. the second - dried and calcined synthetic zeolite. The second column is cooled with liquid nitrogen.

Additional purification of argon with copper oxide at a temperature of 700 * C - 750 * C, followed by removal of moisture and carbon dioxide in two columns, the first of which is filled with anhydrone. the second - synthetic zeolite.

T.22.2 Chromatograph calibration

The calibration of the chromatographic installation (Figure G.3) is carried out using the absolute calibration method, using calibration mixtures. Based on the chromatograms of the calibration mixtures, a calibration traffic is constructed depending on the height of the methane face, reduced to the sensitivity of the M1 recorder, in millimeters, on the volume fraction of methane, in percent.

The calibration is checked once every 3 ms.

Graduation conditions. Argon carrier gas flow rate is 60-70 cm 3 /min. hydrogen 30-40 cm 3 /min, air 150-200 cm 3 /min. the dose of the calibration mixture is 1-2 cm 3. The sensitivity of the recorder is established experimentally, depending on the composition of the calibration mixture and the type of chromatograph.

GOST 10157-2016

) - score with the analyzed gas. 2 - point with nitrogen gas (nitrogen, hydrogen or hydrogen): 3 - cylinder reducer: 4 - fine adjustment valve; S - dispenser, b - reactor: 7 - flame ionization detector: 8 - measuring device

Figure D.2 - Chromatographic installation

D2.2.3 Conducting analysis

A sample of the analyzed gas is introduced into the chromatograph using a dispenser. Reactor temperature, carrier gas flow. hydrogen and air, the dose of the analyzed gas must be identical to that adopted during calibration of the device.

The sensitivity of the recorder is chosen such that the peak of the detected impurity is maximum within the chart strip of the recorder.

D.2.2.4 Processing results

Volume fraction of the sum of carbon-containing compounds in terms of C0 2 X.%. equal to the volume fraction of methane present in the analyzed gas and formed during the hydrogenation of carbon oxide and dioxide, which is determined from the calibration graph based on the height of the methane peak, reduced to the sensitivity of the M1 recorder.

The result of the analysis is taken as the arithmetic mean value of two parallel determinations, the permissible differences between which should not exceed 15% relative to the average result of the determined value with a confidence probability of 0.95.

GOST 10157-2016

Bibliography

Technical Regulations of the Customs Union “Safety requirements for food additives, flavorings and technological aids” (TP TS-029-2012) (Adopted by decision of the Council of the Eurasian Economic Commission dated July 20, 2012 N9 58)

GOST 10157-2016

UDC 661.939.3.006.354 MKS 71.060.10

Key words: gaseous argon, liquid argon, technical specifications

Editor A.E. Elin Technical editor V.N. Prusakova Corrector MM. Pershina Computer layout E.E. Krugova

Delivered for recruitment on 10/26/2016. Signed for publication on November 21, 2016. Format 60*64!4 Typeface Ariel Uel. oven clause 6.26. Uch.-im L. 3.03 Circulation 43 em. Behind*. 286S.

Prepared based on the electronic version provided by the developer of the standard.

Imaio and printed by FSUE "STANDARTINFORM". 12399S Moema. Grenade Lane.. 4.

GOST 10157-79

INTERSTATE STANDARD

ARGON GAS AND LIQUID

TECHNICAL CONDITIONS

IPC PUBLISHING HOUSE OF STANDARDS

Moscow

INTERSTATE STANDARD

Date of introduction 01.07.80

This standard applies to gaseous and liquid argon obtained from air and residual gases of ammonia production and intended for use as a protective medium when welding, cutting and melting active and rare metals and alloys based on them, aluminum, aluminum and magnesium alloys, stainless chromium-nickel heat-resistant alloys and alloy steels of various grades, as well as during the refining of metals in metallurgy. Formula A r. Atomic mass (according to international atomic masses 1985) - 39.948. (Changed edition, Amendment No. 1, 2).

1. TECHNICAL REQUIREMENTS

1.1. Gaseous and liquid argon must be manufactured in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner.1.2. In terms of physical and chemical parameters, gaseous and liquid argon must comply with the standards specified in table. 1.

Table 1

Indicator name	Norm
Indicator name	Top grade	First grade
1. Volume fraction of argon, %, not less
2. Volume fraction of oxygen, %, no more
3. Volume fraction of nitrogen, %, no more
4. Volume fraction of water vapor, %, no more, which corresponds to the temperature of saturation of argon with water vapor at a pressure of 101.3 kPa (760 mm Hg), °C, no more			5. Volume fraction of the sum of carbon-containing compounds in terms of CO 2,%, no more

Notes: 1. The volume fraction of the sum of carbon-containing compounds is not standardized in gaseous and liquid argon produced from air if electronic hydrogen, which does not contain impurities of carbon-containing compounds and alkali, as well as hydrogen from coke oven gas and synthesis gas, specially purified in ammonia, is used to purify raw argon. productions 2. The standards for liquid argon indicated in the table correspond to the indicators for gaseous argon obtained by complete evaporation of a sample of liquid argon. 3. It is allowed to reduce the amount of liquid argon due to its evaporation during transportation and storage by no more than 10%. (Changed edition, Amendment No. 1, 2, 3).1.3. NCP codes for gaseous and liquid argon are given in table. 2.

table 2

(Changed edition, Amendment No. 2).

2. SAFETY REQUIREMENTS

2.1. Argon is non-toxic and non-explosive, but it is dangerous to life: when inhaled, a person instantly loses consciousness, and death occurs within a few minutes. In a mixture of argon with other gases or in a mixture of argon with oxygen, when the volume fraction of oxygen in the mixture is less than 19%, oxygen deficiency develops, and with a significant decrease in the oxygen content, suffocation occurs.2.2. Argon gas is heavier than air and can accumulate in poorly ventilated areas near the floor and in pits, as well as in the internal volumes of equipment intended for the production, storage and transportation of gaseous and liquid argon. At the same time, the oxygen content in the air decreases, which leads to oxygen deficiency, and with a significant decrease in oxygen content - to suffocation, loss of consciousness and death of a person. 2.1; 2.2. (Changed edition, Amendment No. 2).2.3. In places where argon gas may accumulate, it is necessary to monitor the oxygen content in the air using automatic or manual instruments with a device for remote air sampling. The volume fraction of oxygen in the air must be at least 19%.2.4. Liquid argon is a low-boiling liquid that can cause frostbite to the skin and damage to the mucous membrane of the eyes. When sampling and analyzing liquid argon, it is necessary to wear safety glasses.2.5. Before carrying out repair work or inspecting a previously used transport or stationary container of liquid argon, it must be warmed to ambient temperature and purged with air. It is allowed to start work when the volume fraction of oxygen inside the container is at least 19%.2.6. When working in an argon atmosphere, it is necessary to use an insulating oxygen device or a hose gas mask.2.7. The operation of cylinders filled with argon gas must be carried out in accordance with the rules for the design and safe operation of pressure vessels approved by the USSR State Mining and Technical Supervision.

3. ACCEPTANCE RULES

3.1. Gaseous and liquid argon are taken in batches. A batch is considered to be any quantity of a product that is homogeneous in terms of quality and documented in one quality document. When argon is supplied in auto-recipients or transport tanks, each tank or each auto-recipient is considered a batch. Each batch of liquid and gaseous argon must be accompanied by a quality document containing the following data: name manufacturer and its trademark; name of the product, its grade; date of manufacture; batch number, cylinder number (for argon gas); volume of argon gas in cubic meters and mass of liquid argon in tons or kilograms (see Appendix 1); results analyzes performed or confirmation of product compliance with the requirements of this standard; designation of this standard; type of hydrogen used to purify raw argon. (Changed edition, Amendment No. 2).3.2. To determine the volume fraction of oxygen and the volume fraction of water vapor, one cylinder is selected from the total number of cylinders simultaneously filled with argon from a common pipeline on one or more filling manifolds; to determine the volume fraction of nitrogen, two cylinders are selected from simultaneously filled on each filling manifold. If unsatisfactory results are obtained the results of the analysis for at least one indicator, a repeated analysis is carried out on it on a double sample. The results of the repeated analysis apply to all simultaneously filled cylinders. The volume fraction of the amount of carbon-containing compounds is determined in samples taken every 8 hours from the common pipeline of argon gas supplied to the collectors. If unsatisfactory analysis results are obtained, repeated analyzes are carried out, selected from 2% of the cylinders filled within 8 hours. The results of repeated analyzes apply to all cylinders filled during the specified period of time. To control the argon pressure in the filled cylinders, 10% of the cylinders are selected from the shift output. (Changed edition, Amendment No. 1, 2, 3).3.3. To control the quality of argon gas by the consumer, 10% of the cylinders from the batch are selected, but at least two cylinders for a batch of less than 20 cylinders. The pressure in selected cylinders is checked. 3.4. To control the quality of argon gas transported in auto-recipients, a sample is taken from each auto-recipient. 3.5. To control the quality of liquid argon, a sample is taken from each transport tank. The manufacturer is allowed to take a sample of liquid argon from a stationary container before filling tankers. 3.6. If you receive unsatisfactory results of the analysis according to paragraphs. 3.3; 3.4 and 3.5, for at least one of the indicators, a repeated analysis is carried out on it on a double sample. The results of the re-analysis apply to the entire batch.

4. METHODS OF ANALYSIS

4.1. Sampling4.1.1. A sample of argon gas is taken from a filled cylinder at a pressure not lower than (14.7 ± 0.5) MPa (150 ± 5) kgf/cm 2 or (19.6 ± 1) MPa (200 ± 10) kgf/cm 2 and temperature from 15 to 30 °C, directly into the analysis device using a reducer or fine adjustment valve and a steel or copper connecting tube from the sampling point to the device. The reducer or valve is flushed with the analyzed gas by raising the pressure twice to 10 kgf/cm 2 and releasing the pressure; the connecting tube is purged with at least ten times the volume of the gas being analyzed. When determining the volume fraction of water vapor, a sample is taken through a stainless steel tube. (Changed edition, Amendment No. 2, 3).4.1.2. A sample of liquid argon is taken into the installation (Fig. 1), the main parts of which are:

1 - rubber tube with a clamp; 2 - copper tube 6 ´ 1; 3 - cover; 4 - rubber tube; 5 - coil evaporator; 6 - vessel with water; 7 - cryogenic vessel; 8 - stainless steel tube 3 ´ 0.7; 9 - gasket

cryogenic vessel SK-6, designed for a pressure of 0.03 MPa (0.3 kgf/cm 2), with a lid equipped with two tubes, one of which reaches the bottom of the vessel, the second is short, closed with a clamp and a coil evaporator from a DKRNM 3 pipe ´0.5 ND MZ according to GOST 617, 500 mm long. Before taking a sample of liquid argon, the cryogenic vessel is cooled by pouring 50 - 100 cm 3 of the analyzed liquid argon. The remaining liquid that has not evaporated is poured out of the vessel and a sample of liquid argon is immediately poured into it, filling the vessel to approximately 1/2 of the volume. With the clamp open 1 close the cryogenic vessel with a lid and attach to it a coil evaporator immersed in a vessel with heated water (50 - 60 °C). A short tube is connected to a cylinder of premium argon gas through a pressure reducing valve, which regulates the rate at which liquid argon enters the evaporator. It is possible to take a sample of liquid argon directly into the instrument for analysis through a coil evaporator. In this case, a coil evaporator, immersed in a vessel with water, is connected to the valve of a container with liquid argon using a stainless steel tube with an internal diameter of 1.5-2.5 mm. (Changed edition, Amendment No. 1, 2, 3).4.2 . Determination of the volume fraction of argon4.2.1. The volume fraction of argon (X) in percent is calculated from the difference between 100 and the sum of the volume fractions of impurities according to the formula

X = 100 - (X 1 + X 2 + X 3 + X 4) ,

where X 1 is the volume fraction of oxygen, %; X 2 is the volume fraction of nitrogen, %; X 3 is the volume fraction of water vapor, %; X 4 is the volume fraction of the sum of carbon-containing compounds in terms of CO 2, %; (Changed edition, Change No. 2, 3). 4.3. Determination of oxygen volume fraction 4.3.1 Flask Kn-1-100 according to GOST 25336. Pipettes with a capacity of 2, 10 and 25 cm 3. Burettes with a capacity of 1 and 5 cm3. General purpose laboratory scales with a maximum weighing limit of 200 g, 2nd class of accuracy. The installation for determining oxygen consists of a vessel for analysis, a bottle for an absorption solution with a capacity of 5 - 10 dm 3 with a drain tube (siphon) and test tubes for colorimetry (Fig. 2a).

I – vessel connection A with atmosphere; II – valve closed;
III – vessel connection A with a vessel B

1 – one-way valve; 2 – two-way valve

The analysis vessel of type SV-7631 MZ (Fig. 2) has two volumes - A and B, separated by a two-way valve 2, equipped with an extension for connecting to the sampling site, and valve 1 for introducing an absorption solution into the vessel. The capacity of volume A is about 5 dm 3, volume B about 25 cm 3. Argon gas according to this standard. Nitrogen gas according to GOST 9293, technical, 1st grade. Aqueous ammonia according to GOST 3760, solutions with a mass fraction of 25 and 4%. Ammonium chloride according to GOST 3773. Distilled water according to GOST 6709. Potassium iodide according to GOST 4232, solution with a mass fraction of 10%. Acetic acid according to GOST 61, x. h., ice. Soluble starch according to GOST 10163, solution with a mass fraction of 1%. Sodium sulfate (sodium thiosulfate) 5-water according to GOST 27068, concentration solution with (Na 2 S 2 O 3) = 0.05 mol/dm 3. Copper (II) sulfate 5-water according to GOST 4165, concentration solution with (1/2 CuSO 4) = 0.05 mol/dm 3. Copper monochloride in accordance with GOST 4164. Round copper electrical wire, type MM, with a diameter of 0.8-2.5 mm, in the form of a spiral. Crane lubricant. Copper monochloride ammonia solution (absorption solution); prepared at the rate of 12 g of copper monochloride, 36 g of ammonium chloride, 145 cm 3 of ammonia solution with a mass fraction of 25% per 1 dm 3 of water. The solution is prepared in a bottle filled with copper wire spirals. Water and an ammonia solution are poured into the bottle, then weighed amounts of ammonium chloride and copper monochloride are added. The solution is purged with argon until the salts are completely dissolved and the solution becomes discolored, after which it is protected from air access. A solution of copper sulfate concentration with (1/2 CuSO 4) = 0.05 mol/dm 3 is prepared as follows: 12.484 g of freshly recrystallized copper sulfate is dissolved in water in a flask with a capacity of 1 dm 3. The titer of the solution is determined by the iodometric method. The iodine released by adding 10 cm 3 of potassium iodide solution and 2 - 3 cm 3 of acetic acid to 25 cm 3 of the analyzed solution is titrated with a solution of sodium thiosulfate in the presence of starch until the solution becomes discolored. The correction factor (K 1) for a copper sulfate solution is calculated as the quotient of dividing by 25 the volume of sodium sulfate solution used for titration. Sample solutions are prepared in test tubes for colorimetry, into each of which a solution of copper sulfate is poured in the quantities indicated in the table. 3, and then bring the volume of the solution to 25 cm 3 with an ammonia solution with a mass fraction of 4%. Shelf life of sample solutions is 6 months.

Table 3

Sample solution number	The volume of copper sulfate solution concentration is exactly 0.05 mol/dm 3, cm 3	The volume of oxygen in the sample corresponding to the color of the solution, cm 3

Note. The volume of oxygen equivalent to 1 cm 3 of copper sulfate solution with a concentration of 0.05 mol/dm 3 is equal to 0.05/1000 ´ 11200/2 ´ 293/273 = 0.300 cm 3 at 20 ° C and 101.3 kPa (760 mm Hg . Art.). If the concentration of the copper sulfate solution is not exactly 0.05 mol/dm 3, then the values given in column 3 are multiplied by the coefficient K 1. (Changed edition, Amendment No. 1, 2, 3). 4.3.2 . Carrying out the analysis Before carrying out the analysis, the vessel is washed with a chromium mixture, then with water and dried in a stream of nitrogen. Open the taps 1 and 2 and attach the analysis vessel to the sampling site. Purge the vessel with at least ten times the volume of the gas being analyzed. Reducing the gas flow, close the tap 1 , then tap 2 and disconnect the device from the sampling site. The gas pressure in the device is equalized with atmospheric pressure by quickly turning tap 2, the tip of which is first immersed in water. The barometric pressure and ambient temperature are noted. Volume B is filled through tap 1 with an absorption solution, after first draining the first portion of the solution from the siphon. Tap 1 close and select a sample solution that matches the color of the solution in volume B. Opening tap 2 (with the tap closed 1 ) pour the absorption solution into volume A and vigorously shake the vessel until the solution completely absorbs oxygen from the gas being analyzed. Return the solution to volume B and select a sample solution that matches the color of the solution in volume B. 4.3.3. Processing of results The volume fraction of oxygen (X 1) in percent is calculated using the formula

where V is the volume of the gas sample, equal to the capacity of volume A, cm 3; V 1 is the volume of oxygen corresponding to the selected reference solution before oxygen absorption, cm 3 ; V 2 - the volume of oxygen corresponding to the selected sample solution after oxygen absorption, cm 3; K 2 - the coefficient for bringing the volume of dry gas to 20 ° C and 101.3 kPa (760 mm Hg) is determined from the table given in reference appendix 2. The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the relative discrepancy between which does not exceed the permissible discrepancy equal to 15%. The volume fraction of oxygen can be determined by multi-scale instruments with a galvanic cell with a solid electrolyte (in this case, the volume fraction of hydrogen and flammable impurities should not exceed 1% of the measured volume fraction of oxygen), as well as from the filling pipeline with industrial automatic gas analyzers of continuous action in accordance with GOST 13320 with a relative error of no more than 10%, for example, type GL. In case of disagreement in the assessment of the volume fraction of oxygen, the analysis is carried out using the colorimetric method with using a solution of copper chloride according to clause 4.3.2. The permissible relative total error of the analysis result is ± 30% with a confidence probability of P = 0.95. (Changed edition, Amendment No. 2, 3).4.4. Determination of the volume fraction of nitrogen 4.4.1 . Equipment Spectral gas analyzers of various types (“Light”, etc.) with a relative error of no more than 15%. Test gas mixtures with a volume fraction of nitrogen in argon of 5 ppm - GSO No. 3992-87, 10 ppm - GSO No. 3994-87 , 20 million -1 - GSO No. 3995-87, 50 million -1 - GSO No. 3997-87, 90 million -1 - GSO No. 3994-87 according to the State Register. 4.4.2. Carrying out the analysis The principle of operation of the gas analyzer is based on measuring the intensity of the radiation of the molecular band of nitrogen excited by an electric discharge in the analyzed gas. Preparation for the analysis and its implementation are carried out in accordance with the operating instructions of the device. 4.4 - 4.4.2. (Changed edition, Amendment No. 2). 4.4.3 . Processing of results The volume fraction of nitrogen (X 2) in percent is determined in accordance with the steady-state readings of the device. The volume fraction of nitrogen can be determined by the gas adsorption chromatographic method using a chromatograph with a highly sensitive thermal conductivity detector with a threshold sensitivity for nitrogen not exceeding 5 million -1. The volume fraction of nitrogen in argon can be determined by other instruments with a relative error of no more than 15%. In case of disagreement in the assessment of the volume fraction of nitrogen, the analysis is carried out by the spectral method. (Changed edition, Amendment No. 2, 3). 4.4.4. (Deleted, Amendment No. 2).4.5. Determination of the volume fraction of water vapor 4.5.1 . Equipment Coulometric gas moisture meters, designed to measure microconcentrations of water vapor, with a relative measurement error of no more than 10% at concentrations from 0 to 20 million -1 (ppm) and no more than 5% at higher concentrations. 4.5.2. Carrying out the analysis The coulometric method is based on the continuous quantitative extraction of water vapor from the test gas with a hygroscopic substance and the simultaneous electrolytic decomposition of the extracted water into hydrogen and oxygen, while the electrolysis current is a measure of the concentration of water vapor. The device is connected to the sampling site with a stainless steel tube. The gas flow rate is set to (50 ± 1) cm 3 /min. The measurement range switch is set so that the instrument readings are within the second third of the measurement scale, graduated in parts per million (ppm). The electrolysis current is measured with a microammeter. The temperature of the cylinder with the analyzed gas must be at least 15 °C. The analysis is carried out according to the instructions supplied with the device. 4.5.3. Processing of results The volume fraction of water vapor (X 3) in ppm is determined in accordance with the steady-state readings of the device. It is possible to determine the volume fraction of water vapor by the condensation method given in Appendix 4. In case of disagreement in the assessment of the volume fraction of water vapor, the analysis is carried out using the coulometric method. 4.5 - 4.5.3. (Changed edition, Amendment No. 3).4.6. Determination of the volume fraction of the sum of carbon-containing compounds in terms of CO 2 4.6.1 . Equipment, reagents and solutions The analysis setup (Fig. 4) consists of an electric furnace designed to heat up to 900 ° C, a quartz tube with an internal diameter of 25 to 30 mm filled with copper oxide, an absorber (Fig. 5) and a gas drum counter with a liquid seal type RG-700.Burettes with a capacity of 25 and 50 cm 3 with a division price of 0.1 cm 3 .Pipettes with a capacity of 20 cm 3 .Flask type P or Kn according to GOST 25336 with a capacity of 1000 cm 3 .General purpose laboratory scales of the 2nd class of accuracy with the highest weighing limit 200 g. Mechanical stopwatch. Argon gas, additionally purified from carbon dioxide, using an alkaline absorber of any type or low-temperature adsorption to a residual volume fraction of no more than 5 ´ 10 -5%. Distilled water according to GOST 6709, freshly boiled. Barium chloride according to GOST 4108. Hydrochloric acid, concentration solution with (HCL) = 0.01 mol/dm 3 (0.01 n); prepared from hydrochloric acid fixanal. Copper (II) oxide according to GOST 16539.

1 – electric oven; 2 – quartz tube; 3 – copper oxide; 4 – absorber; 5 – gas drum meter ________ * Damn. 3 (Deleted, Amendment No. 2).

1 – five full turns of a tube with a diameter of (6 ± 1) mm; 2 – glass lintel;
3 – junction point of the gas supply line

Rectified technical ethyl alcohol, highest grade, according to GOST 18300, solution with a mass fraction of 60%. Phenolphthalein, alcohol solution with a mass fraction of 0.1%. Barium hydroxide 8-water according to GOST 4107, solution concentration with (1/2 Va (OH) ) 2) = 0.01 mol/dm 3 (0.01 n); prepared as follows: 1.8 g Ba (OH) 2 8H 2 O and 0.35 g BaCl 2 2H 2 O are dissolved in 200-300 cm 3 of hot water in a 1 dm 3 volumetric flask, the cooled solution is brought to the mark with water and filtered in a stream of argon. The solution must be protected from atmospheric air during storage and use. (Changed edition, Amendment No. 1, 2, 3). 4.6.2. Carrying out the analysis Determine the concentration of the barium hydroxide solution (control sample). To do this, 20 cm 3 of solution is taken into an absorber and titrated in a stream of argon, purified from carbon dioxide, with a solution of hydrochloric acid in the presence of 2 - 3 drops of phenolphthalein solution. The analyzed argon is passed through a tube with copper oxide heated to a temperature of 800 - 850 ° C, for 10 minutes at a rate of about 5 dm 3 /h and released into the atmosphere. Then an absorber is connected to the tube, into which 20 cm 3 of barium hydroxide solution is poured and 20 dm 3 of the analyzed argon is passed through the installation, maintaining a gas speed of about 10 dm 3 / h. After this, the solution in the absorber is titrated in a stream of argon, purified from carbon dioxide, with hydrochloric acid in the presence of 2 - 3 drops of phenolphthalein solution until the solution becomes discolored. 4.6.3 . Processing the results The volume fraction of the amount of carbon-containing compounds in terms of CO 2 (X 4) in percent is calculated using the formula

Where V 3- volume of hydrochloric acid solution consumed for titration of the control sample, cm 3; V 4 - volume of hydrochloric acid solution consumed for titrating the solution after absorption of carbon dioxide, cm 3; 0.12 - coefficient taking into account the equivalent ratio of barium hydroxide solution concentration c (1 / 2 Ba(OH) 2) = 0.01 mol/ dm 3 and carbon dioxide; V n is the volume of gas taken for analysis, reduced to normal conditions, cm 3. The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the relative discrepancy between which does not exceed the permissible discrepancy equal to 10%. It is allowed to determine the volume fraction of the amount of carbon-containing compounds in recalculation to CO 2 by gas chromatographic methods given in recommended Appendix 5. In case of disagreement in the assessment of the volume fraction of the sum of carbon-containing compounds in terms of CO 2, the analysis is carried out using the titrometric method. The permissible relative total error of the analysis result is ± 25% with a confidence probability of P - 0.95. (Changed edition, Amendment No. 1, 2, 3).4.7. The volume fractions of oxygen and the amount of carbon-containing compounds in terms of CO 2 can be determined by the gas adsorption chromatographic method using a chromatograph with a highly sensitive argon discharge detector with a threshold sensitivity of no higher than 0.5 ppm for each impurity being determined. (Changed edition, Amendment No. 1, 2).

5. PACKAGING, LABELING, TRANSPORTATION AND STORAGE

5.1. Packaging, marking, transportation and storage of gaseous and liquid argon - in accordance with GOST 26460. Gaseous argon belongs to class 2, subclass 2.1, classification code - 2111, danger sign drawing number - 2, UN number - 1006. Liquid argon belongs to class 2, subclass 2.1, classification code - 2115, danger sign drawing number - 2, UN number - 1951. The nominal pressure of argon at 20 ° C during filling, storage and transportation of cylinders and auto-recipients should be (14.7 ± 0.5) MPa [( 150 ± 5) kgf/cm 2 ] or (19.6 ± 1.0) MPa [(200 ± 10) kgf/cm 2 ]. Return cylinders and auto recipients must have a residual argon pressure of at least 0.05 MPa (0. 5 kgf/cm 2). (Changed edition, Amendment No. 2, 3).

6. MANUFACTURER WARRANTY

6.1. The manufacturer guarantees that the quality of gaseous and liquid argon meets the requirements of this standard provided that the consumer complies with the storage and transportation conditions (Amended edition, Amendment No. 2). 6.2. The guaranteed shelf life of argon gas is 18 months. from the date of manufacture. (Changed edition, Amendment No. 1).

ANNEX 1

Information

CALCULATION OF THE QUANTITY OF GAS
AND LIQUID ARGON

1. The volume of argon gas in a cylinder (V n) in m 3 under normal conditions is calculated using the formula

V n = K× V b,

Where K is the coefficient for calculating the volume of gas in the cylinder, given in the table, taking into account the compressibility of argon, the pressure and temperature of the gas in the cylinder; V b - average capacity of the cylinder, dm 3. The arithmetic mean of capacities of at least 100 cylinders is taken as the statistical average. The value of the coefficient (K) is calculated using the formula

Where P is the gas pressure in the cylinder, measured by a pressure gauge, kgf/cm 2 ; 0.968 - conversion factor of technical atmospheres (kgf/cm2) into physical atmospheres; t- gas temperature in the cylinder when measuring pressure, ° C; Z - argon compressibility coefficient at temperature t. For example, when supplying argon gas in cylinders in accordance with GOST 949 with a capacity of 40 dm 3, the volume of gas in the cylinder is: at a pressure of 150 kgf/cm 2 at 20 ° C

0.155 ´ 40 = 6.20 m3;

At a pressure of 200 kgf/cm 2 at 20 ° C

0.206 ´ 40 = 8.24 m3.

(Changed edition, Amendment No. 2). 2. The amount of liquid argon in tanks is measured in tons or kilograms. When converting the mass or volume of liquid argon to m 3 of gaseous argon under normal conditions, use the formulas given below.

Or ,

Where m- mass of liquid argon, t; Vand- volume of liquid argon, dm 3. 1.662 - density of argon gas under normal conditions, kg/m3; 1.392 - density of liquid argon at normal pressure, kg/dm 3.

Coefficient (K) for calculating the volume of gas in a cylinder in m3
under normal conditions 20 ° C and 101.3 kPa (760 mmHg)

Gas temperature in the cylinder, °C	Excessive gas pressure in the cylinder, MPa (kgf/cm2)
	9,8	11,8	13,7	14,2	14,7	15,2	15,7	16,2	16,7	17,7	19,6	21,6														0,157	0,193	0,231	0,240	0,249	0,258	0,267	0,276	0,284	0,300	0,331			0,145	0,178	0,211	0,219	0,227	0,236	0,243	0,251	0,259	0,274	0,303			0,140	0,171	0,203	0,211	0,218	0,226	0,234	0,241	0,248	0,263	0,291			0,135	0,165	0,195	0,203	0,210	0,217	0,224	0,232	0,239	0,253	0,280			0,131	0,159	0,188	0,195	0,202	0,209	0,216	0,223	0,230	0,243	0,269			0,127	0,154	0,181	0,188	0,195	0,202	0,209	0,215	0,222	0,235	0,259			0,123	0,149	0,175	0,182	0,189	0,195	0,202	0,208	0,215	0,227	0,252			0,120	0,145	0,170	0,177	0,183	0,189	0,195	0,202	0,208	0,220	0,243			0,116	0,141	0,165	0,171	0,178	0,184	0,190	0,196	0,202	0,213	0,236			0,113	0,137	0,161	0,167	0,173	0,178	0,184	0,190	0,196	0,207	0,229			0,110	0,134	0,157	0,162	0,168	0,174	0,179	0,185	0,190	0,201	0,223			0,108	0,132	0,153	0,158	0,164	0,169	0,175	0,180	0,185	0,196	0,217			0,105	0,128	0,149	0,154	0,159	0,165	0,170	0,175	0,181	0,191	0,212			0,103	0,124	0,145	0,150	0,155	0,161	0,166	0,171	0,176	0,186	0,206			0,101	0,121	0,142	0,147	0,152	0,157	0,162	0,167	0,172	0,182	0,201			0,099	0,119	0,139	0,144	0,149	0,154	0,158	0,163	0,168	0,178	0,196			0,097	0,116	0,136	0,140	0,145	0,150	0,155	0,160	0,164	0,174	0,192			0,095	0,114	0,133	0,137	0,142	0,147	0,152	0,156	0,161	0,170	0,188			0,091	0,109	0,128	0,132	0,137	0,141	0,146	0,150	0,154	0,163	0,180

APPENDIX 2

Information

The value of coefficient K 2 to bring the volume of gas to normal conditions

Temperature, ° WITH

Barometer readings, kPa (mm Hg)

93,3

94,6

96,0

97,2

98,6

100,0

101.3

102,6

K 2

APPENDIX 2 . (Changed edition, Amendment No. 1). APPENDIX 3. (Deleted, Amendment No. 2).

APPENDIX 4

Mandatory

DETERMINATION OF THE VOLUME FRACTION OF WATER VAPOR BY THE CONDENSATION METHOD The volume fraction of water vapor is determined by condensation-type devices with a threshold sensitivity not higher than 1.5 million -1 (pmm). The relative error of the device should not exceed 10%. The method is based on measuring the temperature of gas saturation with water vapor when dew appears on a cooled mirror surface. The analysis is carried out according to the instructions supplied with the device. The volume fraction of water vapor in accordance with the found saturation temperature is determined from the table. 1.

Table 1

ppm)

Saturation temperature,oWITH

Volume fraction of water vapor, ppm (ppm)

Saturation temperature,oWITH

Note. A volume fraction equal to 1 ppm corresponds to 1 ´ 10 -4%. The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the relative discrepancy between which does not exceed the permissible discrepancy of 10%. The permissible relative total error of the analysis result is ±25% with a confidence probability of P = 0.95. APPENDIX 4. (Changed edition, Amendment No. 3).

APPENDIX 5

Recommended DETERMINATION OF THE VOLUME FRACTION OF THE SUM OF CARBON-CONTAINING COMPOUNDS BY GAS CHROMATOGRAPHIC METHODS A. Determination of the volume fraction of carbon dioxide obtained from the oxidation of carbon-containing compounds with copper oxide (according to clause 4.6.2 of this standard). 1. Equipment, materials and reagents Chromatograph with a thermal conductivity detector with a sensitivity threshold for propane with a helium carrier gas not higher than 2 ´ 10 -5 mg/cm 3 and a gas chromatographic column 1.4 m long, 4 mm internal diameter, filled with active carbon . The hub is U-shaped. For production, a stainless steel tube 6 ´ 1 mm, 500 mm long, is taken. The concentrator is filled with crushed laboratory glass. A glass adapter (Fig. 1) with an extension and a plug for introducing the sample is attached to the concentrate. The Dewar flask is glass, with a capacity of about 0.5 dm 3. Gas drum meter (with liquid seal) type RG-700. Auxiliary equipment for chromatographic analysis: measuring magnifier according to GOST 25706 16 x magnification with a division value of 0.1 mm; metal ruler according to GOST 427;

Glass adapter with stopper

A set of “Fizpribor” sieves or sieves of a similar type; medical injection syringes, Record type according to GOST 22967, capacity 2, 5, 10 cm 3; mechanical stopwatch; foam flow meter. Technical liquid oxygen in accordance with GOST 6331. Purified gaseous helium with a volume fraction of carbon dioxide of no more than 0.0001%. Test gas mixture with a volume fraction of carbon dioxide in nitrogen of 0.50% - GSO No. 3765-87 according to the State Register. Active carbon, grade SKT, fraction with particles 0.2 - 0.5 mm in size, dried at 150 ° C for 4 hours. Laboratory glass, crushed in a porcelain mortar. The fraction with particles 0.2 - 0.5 mm in size is washed with hot distilled water and dried at 150 ° C for 4 hours. Copper mesh with a cell size of 0.1-0.15 mm or glass fiber according to GOST 10727. 2. Preparation for analysis The gas chromatographic column is filled with active carbon; A layer of glass fiber 8 - 12 mm thick is laid on top of the coal layer. Then the column is fixed in the chromatograph thermostat and, without connecting to the detector, additionally dried at 150 ° C for 8 hours in a flow of carrier gas at a flow rate of 30 cm 3 /min. The concentrator is filled with crushed glass; A copper mesh is laid on top of the glass layer. The filled concentrator is purged with a carrier gas for 3 hours. The volume fraction of carbon dioxide is determined by the absolute calibration method, using a calibration gas mixture (CGM). From 3 to 5 doses of PGS with a volume of 2 to 10 cm 3 are introduced into the chromatograph through a concentrator, which is connected to the chromatograph instead of a replaceable dose with short vacuum tubes. Before administering each dose, flush the concentrator with carrier gas (helium) for 1 minute. Then, stopping the helium supply, place the concentrator in a Dewar flask with liquid oxygen. After 3 minutes, the supply of carrier gas is turned on and a dose of PGS is introduced into its flow through an adapter. After 1 minute, replace the Dewar flask with liquid oxygen with a flask of water heated to 25 - 30 ° C, and record a chromatogram of desorbed carbon dioxide. Based on the PGS chromatograms, a calibration graph is constructed depending on the height of the peak of carbon dioxide in millimeters, reduced to the sensitivity of the recorder (scale) M 1, on the volume of carbon dioxide in each dose ( V 1 ) in milliliters, which is calculated by the formula

Where With ST- volume fraction of carbon dioxide in ASG, %; D ST- dose of PGS, cm 3. Graduation conditions. The temperature of the gas chromatographic column is 150 ° C, the flow rate of carrier gas (helium) is 30 cm 3 /min. The detector supply current and the sensitivity of the recorder are established experimentally depending on the type of chromatograph. The calibration is checked once a month using a gas mixture of carbon dioxide and nitrogen with a carbon dioxide volume fraction set at about 0.5%. 3. Carrying out analysis The chromatograph is connected to the network and switched to normal mode. The concentrator is connected to the switching valve of the chromatograph and purged with at least ten times the volume of helium. At the same time, the flow rate of the analyzed gas is set to about 300 cm 3 /min according to the readings of the foam flow meter. Place the concentrator in a Dewar flask with liquid oxygen. After 3 minutes, the analyzed gas is directed into the concentrate and 3 to 5 dm 3 of gas is passed through, depending on the measured volume fraction of carbon dioxide. The sample volume is measured using the gas meter readings. Having finished sampling, flush the cooled concentrator with helium for 1 - 2 minutes, then replace the Dewar flask with liquid oxygen with a vessel of water heated to 25 - 30 ° C, and record a chromatogram of desorbed carbon dioxide. The temperature of the gas chromatographic column, the flow rate of the carrier gas (helium) and the supply current of the detector must be identical to those adopted during calibration of the device. The recorder scale range is selected such that the carbon dioxide peak is maximum within the recorder chart strip. 4. Processing of results Based on the height of the carbon dioxide peak, reduced to the sensitivity of the recorder Ml, the volume of carbon dioxide in the argon sample is determined from the calibration graph and the volume fraction of carbon dioxide (X) is calculated as a percentage using the formula

Where V 1 is the volume of carbon dioxide in the argon sample according to the calibration curve, cm 3; V is the volume of argon sample, cm3. The result of the analysis is taken as the arithmetic mean of two parallel determinations, the permissible differences between which should not exceed 15% relative to the average result of a certain value with a confidence probability of 0.95. B. Determination of the volume fraction of the sum of carbon-containing compounds with preliminary hydrogenation of carbon monoxide and dioxide 1. Equipment, materials and reagents Chromatograph with a flame ionization detector, with a sensitivity threshold for propane not higher than 2.5 10 -8 mg/s. Reactor-tube made of stainless steel with a diameter of 3 to 5 mm, a length of 100 - 300 mm, filled with a catalyst, placed in an oven designed to be heated to a temperature of 500 ° C. Auxiliary equipment for chromatographic analysis t. 1. Argon gas according to this standard, additionally purified from carbon-containing compounds to a volume fraction of no more than 0.0001%. Technical hydrogen according to GOST 3022 grade A or B, premium grade, additionally purified from carbon-containing compounds to a volume fraction of no more than 0.0001%. Compressed air according to GOST 17433, pollution class no higher than 2. Pure gaseous methane with a volume fraction of the main substance of at least 99.6%. Nickel (II) nitrate 6-water according to GOST 4055. Technical fine-porous silica gel according to GOST 3956, fraction with particle size 0.5 - 1 mm. Test gas mixtures with a volume fraction of methane in the air of 2.5 ppm and 7.5 ppm - GSO No. 3896-87; 10 million -1 - GSO No. 3897-87 according to the State Register. A calibration gas mixture with a volume fraction of carbon dioxide in nitrogen of 50 ppm - GSO No. 3746-87 according to the State Register. 2. Preparation for analysis 2.1. Install a gas chromatographic column (no more than 1 m long) not filled with adsorbent in the chromatograph. The catalyst for filling the reactor is prepared as follows. Dry the silica gel at 150 - 180 ° C for 4 hours in a drying cabinet, place it in a porcelain cup and fill it with a solution of nickel nitrate at the rate of: per 20 g of silica gel about 10 g of Ni (N 0 3) 2 6H 2 0 dissolved in water. Silica gel must be completely immersed in the solution. Excess solvent is evaporated. The mass is calcined at 600 - 800 ° C until the release of nitrogen oxides stops, then cooled, the reactor is filled, connected to the chromatograph and nickel oxide is reduced to metallic nickel in a stream of hydrogen (flow rate 60 cm 3 / min) at 400-500 ° C for 4 hours The activity of the catalyst is checked using a test gas mixture of carbon dioxide in argon. In a reactor connected via a tee to a gas chromatography column (at the gas outlet), carbon dioxide is hydrogenated with hydrogen at 450 - 500 ° C to methane. The methane peak is detected by a flame ionization detector. The volume fraction of carbon dioxide is determined from the height of the methane peak and compared with the nominal content of carbon dioxide in the mixture. The permissible discrepancy between the results is no more than 5%. Additional purification of hydrogen in two columns, the first of which is filled with anhydrone, the second with dried and calcined synthetic zeolite. The second column is cooled with liquid nitrogen. Additional purification of argon with copper oxide at 700 - 750 ° C, followed by removal of moisture and carbon dioxide in two columns, the first of which is filled with anhydrone, the second with synthetic zeolite. 2.2 . Calibration of the chromatograph Calibration of the chromatographic installation (Fig. 3) is carried out using the absolute calibration method, using calibration mixtures. Based on the chromatograms of the calibration mixtures, a calibration graph is constructed of the dependence of the height of the methane peak, reduced to the sensitivity of the recorder Ml, in millimeters, on the volume fraction of methane in percent.

1 - cylinder with the analyzed gas; 2 - cylinder with carrier gas (nitrogen, argon or hydrogen); 3 - cylinder reducer; 4 - fine adjustment valve; 5 - dispenser; 6 - reactor; 7 - flame ionization detector; 8 - measuring device

The calibration is checked once every 3 months. Graduation conditions. The carrier gas consumption of argon is 60 - 70 cm 3 /min, hydrogen 30 - 40 cm 3 /min, air 150 - 200 cm 3 /min, the dose of the calibration mixture is 1 - 2 cm 3. The sensitivity of the recorder is established experimentally, depending on the composition of the calibration mixture and the type of chromatograph. 3. Conducting analysis 3.1. A sample of the analyzed gas is introduced into the chromatograph using a dispenser. The reactor temperature, the flow rate of carrier gas, hydrogen and air, and the dose of the analyzed gas must be identical to those adopted during calibration of the device. The sensitivity of the recorder is chosen such that the peak of the detected impurity is maximum within the chart strip of the recorder. 4. Processing of results 4.1. The volume fraction of the sum of carbon-containing compounds in terms of CO 2 (X 5) in percent is equal to the volume fraction of methane present in the analyzed gas and formed during the hydrogenation of carbon monoxide and dioxide, which is determined from a calibration graph based on the height of the methane peak, reduced to the sensitivity of the recorder Ml. The result of the analysis is taken as the arithmetic mean of two parallel determinations, the permissible differences between which should not exceed 15% relative to the average result of the determined value with a confidence probability of 0.95. APPENDIX 5.

(Changed edition, Amendment No. 2).

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of Chemical Industry of the USSR 2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated November 23, 1979 No. 4496 Change No. 3 was adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 12 dated November 21, 1997) Registered The Technical Secretariat of MGU No. 2699 voted for the adoption of the change:

State name

Name of the national standardization body

The Republic of Azerbaijan

Azgosstandart

Republic of Armenia

Armgosstandard

Republic of Belarus

State Standard of Belarus

The Republic of Kazakhstan

Gosstandart of the Republic of Kazakhstan

Kyrgyz Republic

Kyrgyzstandard

The Republic of Moldova

Moldovastandard

Russian Federation

Gosstandart of Russia

The Republic of Tajikistan

Tajikgosstandart

Turkmenistan

Main State Inspectorate of Turkmenistan

Ukraine

State Standard of Ukraine3. INSTEAD GOST 10157-73

4. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

Number of paragraph, subparagraph, application

4.3.1

GOST 61-75

GOST 6331-78

Appendix 5

GOST 6331-78

GOST 427-75

4.3.1; 4.6.1

GOST 6709-72

4.1.2

GOST 617-90

4.3.1

GOST 9293-74

GOST 949-73

Annex 1

4.3.1

GOST 3022-80

GOST 6331-78

GOST 10727-91

GOST 6331-78

GOST 3760-79

4.3.1

GOST 13320-81

4.3.3

GOST 3773-72

4.3.1

GOST 16539-79

4.6.1

GOST 3956-76

GOST 6331-78

GOST 17433-80

GOST 6331-78

GOST 4055-78

GOST 6331-78

GOST 18300-87

4.6.1

GOST 4107-78

4.6.1

GOST 22967-90

GOST 6331-78

GOST 4108-72

4.6.1

GOST 25336-82

4.3.1; 4.6.1

GOST 4164-79

4.3.1

GOST 25706-83

GOST 6331-78

GOST 4165-78

4.3.1

GOST 26460-85

5.1

GOST 4232-74

4.3.1

GOST 27068-86

4.3.1

5. The validity period was lifted according to Protocol No. 4-93 of the Interstate Council for Standardization, Methodology and Certification (IUS 4-94) 6. EDITION (March 2002) with Amendments No. 1,2,3, approved in March 1985, November 1989, April 1998, (IUS 6-85, 2-90, 7-98)

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page 4

page 5

page 6

page 7

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INTERSTATE STANDARD

ARGON GAS AND LIQUID

TECHNICAL CONDITIONS

Date of introduction 07/01/80

Formula Ar.

Atomic mass (according to international atomic masses 1985) - 39.948.

(Changed edition, Amendment No. 1, 2).

1. TECHNICAL REQUIREMENTS

1.1. Gaseous and liquid argon must be manufactured in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner.

1.2. In terms of physical and chemical parameters, gaseous and liquid argon must comply with the standards specified in table. 1.

Table 1

Notes:

1. The volume fraction of the sum of carbon-containing compounds is not standardized in gaseous and liquid argon produced from air if electronic hydrogen, which does not contain impurities of carbon-containing compounds and alkali, as well as hydrogen from coke oven gas and synthesis gas, specially purified in ammonia production, is used to purify raw argon.

2. The standards for liquid argon indicated in the table correspond to the indicators for gaseous argon obtained by complete evaporation of a sample of liquid argon.

3. It is allowed to reduce the amount of liquid argon due to its evaporation during transportation and storage by no more than 10%.

1.3. NCP codes for gaseous and liquid argon are given in table. 2.

table 2

2. SAFETY REQUIREMENTS

2.2. Argon gas is heavier than air and can accumulate in poorly ventilated areas near the floor and in pits, as well as in the internal volumes of equipment intended for the production, storage and transportation of gaseous and liquid argon. At the same time, the oxygen content in the air decreases, which leads to oxygen deficiency, and with a significant decrease in oxygen content - to suffocation, loss of consciousness and death of a person.

2.1; 2.2. (Changed edition, Amendment No. 2).

2.3. In places where argon gas may accumulate, it is necessary to monitor the oxygen content in the air using automatic or manual instruments with a device for remote air sampling. The volume fraction of oxygen in the air must be at least 19%.

2.4. Liquid argon is a low-boiling liquid that can cause frostbite to the skin and damage to the mucous membrane of the eyes. When sampling and analyzing liquid argon, it is necessary to wear safety glasses.

2.5. Before carrying out repair work or inspecting a previously used transport or stationary container of liquid argon, it must be warmed to ambient temperature and purged with air. It is allowed to start work when the volume fraction of oxygen inside the container is at least 19%.

2.6. When working in an argon atmosphere, it is necessary to use an insulating oxygen device or a hose gas mask.

2.7. The operation of cylinders filled with argon gas must be carried out in accordance with the rules for the design and safe operation of pressure vessels approved by the USSR State Mining and Technical Supervision.

3. ACCEPTANCE RULES

3.1. Gaseous and liquid argon are taken in batches. A batch is considered to be any quantity of a product that is uniform in terms of quality and documented in one quality document.

Each batch of liquid and gaseous argon must be accompanied by a quality document containing the following data:

name of the manufacturer and its trademark;

name of the product, its grade;

date of manufacture;

batch number, cylinder number (for argon gas);

volume of argon gas in cubic meters and mass of liquid argon in tons or kilograms (see Appendix 1);

results of analyzes performed or confirmation of product compliance with the requirements of this standard;

designation of this standard;

a type of hydrogen used to purify raw argon.

3.2. To determine the volume fraction of oxygen and the volume fraction of water vapor, one cylinder is selected from the total number of cylinders simultaneously filled with argon from a common pipeline on one or more filling manifolds; to determine the volume fraction of nitrogen, two cylinders are selected from those simultaneously filled on each filling manifold.

The volume fraction of the sum of carbon-containing compounds is determined in samples taken every 8 hours from the common pipeline of argon gas supplied to the collectors. If unsatisfactory analysis results are obtained, repeated analyzes are carried out, selected from 2% of cylinders filled within 8 hours. The results of repeated analyzes apply to all cylinders filled during the specified period of time.

To control the argon pressure in filled cylinders, 10% of the cylinders from the shift output are selected.

(Changed edition, Amendment No. 1, 2, 3).

3.3. To control the quality of argon gas by the consumer, 10% of the cylinders from the batch are selected, but at least two cylinders for a batch of less than 20 cylinders. The pressure in selected cylinders is checked.

3.4. To control the quality of argon gas transported in auto-recipients, a sample is taken from each auto-recipient.

3.5. To control the quality of liquid argon, a sample is taken from each transport tank. The manufacturer is allowed to take a sample of liquid argon from a stationary container before filling tankers.

3.6. If you receive unsatisfactory results of the analysis according to paragraphs. 3.3; 3.4 and 3.5, for at least one of the indicators, a repeated analysis is carried out on it on a double sample. The results of the re-analysis apply to the entire batch.

4. METHODS OF ANALYSIS

4.1. Sample selection

4.1.1. A sample of argon gas is taken from a filled cylinder at a pressure not lower than (14.7 ± 0.5) MPa (150 ± 5) kgf/cm 2 or (19.6 ± 1) MPa (200 ± 10) kgf/cm 2 and temperature from 15 to 30 °C, directly into the analysis device using a reducer or fine adjustment valve and a steel or copper connecting tube from the sampling point to the device. The reducer or valve is flushed with the analyzed gas by raising the pressure twice to 10 kgf/cm 2 and releasing the pressure; the connecting tube is purged with at least ten times the volume of the gas being analyzed. When determining the volume fraction of water vapor, a sample is taken through a stainless steel tube.

4.1.2. A sample of liquid argon is taken into the installation (Fig. 1), the main parts of which are:

1 - rubber tube with clamp; 2 - copper tube 6 ´ 1; 3 - lid; 4 - rubber tube; 5 - coil evaporator; 6 - a vessel with water; 7 - cryogenic vessel; 8 - stainless steel tube 3 ´ 0.7; 9 - pad

Before taking a sample of liquid argon, the cryogenic vessel is cooled by pouring 50 - 100 cm 3 of the analyzed liquid argon. The remaining liquid that has not evaporated is poured out of the vessel and a sample of liquid argon is immediately poured into it, filling the vessel to approximately 1/2 of the volume.

When clamp is open 1 close the cryogenic vessel with a lid and attach to it a coil evaporator immersed in a vessel with heated water (50 - 60 °C). A short tube is connected to a cylinder of premium argon gas through a pressure reducing valve, which regulates the rate of flow of liquid argon into the evaporator.

It is possible to take a sample of liquid argon directly into the device for analysis through a coil evaporator. In this case, a coil evaporator, immersed in a vessel with water, is connected to the valve of a container with liquid argon using a stainless steel tube with an internal diameter of 1.5 - 2.5 mm.

(Changed edition, Amendment No. 1, 2, 3).

4.2. Determination of the volume fraction of argon

4.2.1. Volume fraction of argon ( X) as a percentage is calculated from the difference between 100 and the sum of the volume fractions of impurities using the formula

X = 100 -(X 1 + X 2 + X 3 +X 4),

Where X 1 - volume fraction of oxygen, %;

X 2 - volume fraction of nitrogen, %;

X 3 - volume fraction of water vapor, %;

X 4 - volume fraction of the sum of carbon-containing compounds in terms of CO 2,%;

(Changed edition, Amendment No. 2, 3).

4.3. Determination of the volume fraction of oxygen

4.3.1

Pipettes with a capacity of 2, 10 and 25 cm3.

Burettes with a capacity of 1 and 5 cm3.

General purpose laboratory scales with a maximum weighing limit of 200 g, 2nd class of accuracy.

The installation for determining oxygen consists of a vessel for analysis, a bottle for an absorption solution with a capacity of 5 - 10 dm 3 with a drain tube (siphon) and test tubes for colorimetry (Fig. 2a).

I - vessel connection A with atmosphere; II - the valve is closed;
III - vessel connection A with a vessel B

1 - one-way valve; 2 - two-way valve

The analysis vessel type SV-7631 MZ (Fig. 2) has two volumes - A And B, separated by a two-way valve 2 , equipped with an extension for connection to the sampling site, and a tap 1 for introducing the absorption solution into the vessel.

Volume capacity A about 5 dm 3, volume B about 25 cm 3.

Argon gas according to this standard.

Round copper electrical wire, type MM, with a diameter of 0.8 - 2.5 mm, in the form of a spiral.

Crane lubricant.

Copper monochloride ammonia solution (absorption solution); prepared at the rate of 12 g of copper monochloride, 36 g of ammonium chloride, 145 cm 3 of ammonia solution with a mass fraction of 25% per 1 dm 3 of water. The solution is prepared in a bottle filled with copper wire spirals. Water and an ammonia solution are poured into the bottle, then weighed amounts of ammonium chloride and copper monochloride are added. The solution is purged with argon until the salts are completely dissolved and the solution becomes discolored, after which it is protected from air access.

A solution of copper sulfate concentration with (1/2 CuSO 4) = 0.05 mol/dm 3 is prepared as follows: 12.484 g of freshly recrystallized copper sulfate is dissolved in water in a flask with a capacity of 1 dm 3. The titer of the solution is determined by the iodometric method.

The iodine released by adding 10 cm 3 of potassium iodide solution and 2 - 3 cm 3 of acetic acid to 25 cm 3 of the analyzed solution is titrated with a solution of sodium thiosulfate in the presence of starch until the solution becomes discolored. Correction factor ( K 1) for a solution of copper sulfate is calculated as the quotient of dividing by 25 the volume of sodium sulfate solution consumed for titration.

Sample solutions are prepared in test tubes for colorimetry, into each of which a solution of copper sulfate is poured in the quantities indicated in the table. 3, and then bring the volume of the solution to 25 cm 3 with an ammonia solution with a mass fraction of 4%.

Shelf life of sample solutions is 6 months.

Table 3

Sample solution number	The volume of copper sulfate solution concentration is exactly 0.05 mol/dm 3, cm 3	The volume of oxygen in the sample corresponding to the color of the solution, cm 3

Note. The volume of oxygen equivalent to 1 cm 3 of a solution of copper sulfate with a concentration of 0.05 mol/dm 3 is equal to

0.05/1000 ´ 11200/2 ´ 293/273 = 0.300 cm 3 at 20 °C and 101.3 kPa (760 mm Hg). If the concentration of the copper sulfate solution is not exactly 0.05 mol/dm 3, then the values given in column 3 are multiplied by the coefficient K 1.

(Changed edition, Amendment No. 1, 2, 3).

4.3.2. Carrying out analysis

Before analysis, the vessel is washed with a chromium mixture, then with water and dried in a stream of nitrogen.

Open the taps 1 And 2 and attach the analysis vessel to the sampling site. Purge the vessel with at least ten times the volume of the gas being analyzed. Reducing the gas flow, close the tap 1 , then tap 2 and disconnect the device from the sampling site. The gas pressure in the device is equalized with atmospheric pressure by quickly turning the tap 2 , the tip of which is pre-immersed in water. Barometric pressure and ambient temperature are noted.

Fill volume B through the tap 1 absorption solution, having previously drained the first portion of the solution from the siphon.

Tap 1 close and select a sample solution that matches the color of the solution in volume B.

Opening the tap 2 (with the tap closed 1 ) pour the absorption solution in volume A and shake the vessel vigorously until the solution completely absorbs oxygen from the gas being analyzed.

Return the solution to volume B and select a sample solution that matches the color of the solution in volume B.

4.3.3. Processing the results

Volume fraction of oxygen (X 1) as a percentage calculated by the formula

Where V- gas sample volume equal to the volume capacity A, cm 3;

V 1 - volume of oxygen corresponding to the selected reference solution before oxygen absorption, cm 3 ;

V 2 - volume of oxygen corresponding to the selected reference solution after oxygen absorption, cm 3 ;

K 2 - coefficient for bringing the volume of dry gas to 20 °C and 101.3 kPa (760 mm Hg) is determined from the table given in reference appendix 2.

The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the relative discrepancy between which does not exceed the permissible discrepancy equal to 15%.

The volume fraction of oxygen can be determined using multi-scale instruments with a galvanic cell with a solid electrolyte (in this case, the volume fraction of hydrogen and flammable impurities should not exceed 1% of the measured volume fraction of oxygen), as well as from the filling pipeline using industrial automatic gas analyzers of continuous operation in accordance with GOST 13320 with a relative error no more than 10%, for example, type GL.

In case of disagreement in the assessment of the volume fraction of oxygen, the analysis is carried out using the colorimetric method using a copper chloride solution according to clause 4.3.2.

Permissible relative total error of the analysis result ±30% with confidence probability P = 0,95.

(Changed edition, Amendment No. 2, 3).

4.4. Determination of the volume fraction of nitrogen

4.4.1. Equipment

Spectral gas analyzers of various types (“Light”, etc.) with a relative error not exceeding 15%.

Test gas mixtures with a volume fraction of nitrogen in argon of 5 ppm - GSO No. 3992-87, 10 ppm - GSO No. 3994-87, 20 ppm - GSO No. 3995-87, 50 ppm - GSO No. 3997 -87, 90 million -1 -GSO No. 3994-87 according to the State Register.

4.4.2. Carrying out analysis

The operating principle of the gas analyzer is based on measuring the radiation intensity of the molecular band of nitrogen excited by an electric discharge in the analyzed gas.

Preparation for analysis and its implementation are carried out in accordance with the operating instructions for the device.

4.4 - 4.4.2. (Changed edition, Amendment No. 2).

4.4.3. Processing the results

Volume fraction of nitrogen ( X 2) as a percentage is determined in accordance with the steady-state readings of the device.

The volume fraction of nitrogen can be determined by the gas adsorption chromatographic method using a chromatograph with a highly sensitive thermal conductivity detector with a threshold sensitivity for nitrogen not higher than 5 ppm.

The volume fraction of nitrogen in argon can be determined by other instruments with a relative error of no more than 15%.

In case of disagreement in the assessment of the volume fraction of nitrogen, the analysis is carried out using the spectral method.

(Changed edition, Amendment No. 2, 3).

4.4.4. (Deleted, Amendment No. 2).

4.5. Determination of the volume fraction of water vapor

4.5.1. Equipment

Coulometric gas moisture meters, designed to measure microconcentrations of water vapor, with a relative measurement error of no more than 10% at concentrations from 0 to 20 million -1 (ppm) and no more than 5% at higher concentrations.

4.5.2. Carrying out analysis

The coulometric method is based on the continuous quantitative extraction of water vapor from the test gas by a hygroscopic substance and the simultaneous electrolytic decomposition of the extracted water into hydrogen and oxygen, while the electrolysis current is a measure of the concentration of water vapor.

The device is connected to the sampling site with a stainless steel tube. The gas flow rate is set to (50 ± 1) cm 3 /min. The measurement range switch is set so that the instrument readings are within the second third of the measurement scale, graduated in parts per million (ppm). The electrolysis current is measured with a microammeter.

The temperature of the cylinder with the analyzed gas must be at least 15 °C. The analysis is carried out according to the instructions supplied with the device.

4.5.3. Processing the results

Volume fraction of water vapor ( X 3) in ppm is determined in accordance with the steady-state readings of the device.

It is allowed to determine the volume fraction of water vapor by the condensation method given in Appendix 4.

In case of disagreement in the assessment of the volume fraction of water vapor, the analysis is carried out using the coulometric method.

4.5 - 4.5.3.

4.6. Determination of the volume fraction of the sum of carbon-containing compounds in terms of CO 2

4.6.1. Equipment, reagents and solutions

The analysis setup (Fig. 4) consists of an electric furnace designed to heat up to 900 °C, a quartz tube with an internal diameter of 25 to 30 mm filled with copper oxide, an absorber (Fig. 5) and a gas drum counter with a liquid seal type RG-700.

Burettes with a capacity of 25 and 50 cm 3 with a division value of 0.1 cm 3.

Pipettes with a capacity of 20 cm 3 .

Hydrochloric acid, concentration solution with (HCL) = 0.01 mol/dm 3 (0.01 n); prepared from fixanal hydrochloric acid.

1 - electric oven; 2 - quartz tube; 3 - copper oxide; 4 - absorber; 5 - gas drum meter

* Crap. 3 (Deleted, Amendment No. 2).

1 - five full turns of the tube with a diameter of (6 ± 1) mm; 2 - glass lintel; 3 - junction point of the gas line

Rectified technical ethyl alcohol, premium grade, according to GOST 18300, solution with a mass fraction of 60%.

Phenolphthalein, alcohol solution with a mass fraction of 0.1%.

Barium hydroxide 8-water according to GOST 4107, solution concentration with (1/2 Ba (OH) 2) = 0.01 mol/dm 3 (0.01 n); prepared as follows: 1.8 g Ba (OH) 2 8H 2 O and 0.35 g BaCl 2 2H 2 O are dissolved in 200 - 300 cm 3 of hot water in a 1 dm 3 volumetric flask, the cooled solution is brought to the mark with water and filtered in a stream of argon. The solution must be protected from atmospheric air during storage and use.

(Changed edition, Amendment No. 1, 2, 3).

4.6.2. Carrying out analysis

The analyzed argon is passed through a tube with copper oxide, heated to a temperature of 800 - 850 °C, for 10 minutes at a rate of about 5 dm 3 / h and released into the atmosphere. Then an absorber is connected to the tube, into which 20 cm 3 of barium hydroxide solution is poured and 20 dm 3 of the analyzed argon is passed through the installation, maintaining a gas speed of about 10 dm 3 / h. After this, the solution in the absorber is titrated in a stream of argon, purified from carbon dioxide, with hydrochloric acid in the presence of 2 - 3 drops of phenolphthalein solution until the solution becomes discolored.

4.6.3. Processing the results

The volume fraction of the amount of carbon-containing compounds in terms of CO 2 (X 4) in percent is calculated using the formula

Where V 3 - volume of hydrochloric acid solution consumed for titration of the control sample, cm 3;

V 4 - volume of hydrochloric acid solution consumed for titrating the solution after absorption of carbon dioxide, cm 3;

0.12 - coefficient taking into account the equivalent ratio of barium hydroxide solution concentration with (1 / 2 Ba(OH) 2) = 0.01 mol/dm 3 and carbon dioxide;

V n is the volume of gas taken for analysis, reduced to normal conditions, cm 3.

The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the relative discrepancy between which does not exceed the permissible discrepancy of 10%.

It is allowed to determine the volume fraction of the sum of carbon-containing compounds in terms of CO 2 using gas chromatographic methods given in recommended Appendix 5.

In case of disagreement in the assessment of the volume fraction of the sum of carbon-containing compounds in terms of CO 2, the analysis is carried out using the titrimetric method.

P - 0,95.

(Changed edition, Amendment No. 1, 2, 3).

4.7. The volume fractions of oxygen and the amount of carbon-containing compounds in terms of CO 2 can be determined by the gas adsorption chromatographic method using a chromatograph with a highly sensitive argon discharge detector with a threshold sensitivity of no higher than 0.5 ppm for each impurity being determined.

(Amended edition, Rev. No. 1, 2).

5. PACKAGING, LABELING, TRANSPORTATION AND STORAGE

5.1. Packaging, labeling, transportation and storage of gaseous and liquid argon - in accordance with GOST 26460.

Argon gas belongs to class 2, subclass 2.1, classification code - 2111, danger sign drawing number - 2, UN number - 1006.

Liquid argon belongs to class 2, subclass 2.1, classification code - 2115, danger sign drawing number - 2, UN number - 1951.

The nominal argon pressure at 20 °C during filling, storage and transportation of cylinders and auto-recipients should be (14.7 ±0.5) MPa [(150 ±5) kgf/cm2] or (19.6 ±1.0) MPa [(200 ±10) kgf/cm2].

(Amended edition, Rev. No. 2, 3).

6. MANUFACTURER WARRANTY

(Changed edition, Amendment No. 2).

6.2. The guaranteed shelf life of argon gas is 18 months. from the date of manufacture.

(Changed edition, Amendment No. 1).

ANNEX 1

Information

CALCULATION OF THE AMOUNT OF GASEOUS AND LIQUID ARGON

1. Volume of argon gas in the cylinder ( Vn) in m 3 under normal conditions is calculated by the formula

V n= K × V b,

Where K- coefficient for calculating the volume of gas in the cylinder, given in the table, taking into account the compressibility of argon, pressure and temperature of the gas in the cylinder;

V b - average capacity of the cylinder, dm 3. The arithmetic mean of capacities of at least 100 cylinders is taken as the statistical average.

Coefficient value ( K) is calculated using the formula

Where P- gas pressure in the cylinder, measured by a pressure gauge, kgf/cm 2 ;

0.968 - conversion factor of technical atmospheres (kgf/cm2) into physical atmospheres;

t- gas temperature in the cylinder when measuring pressure, °C;

Z- argon compressibility coefficient at temperature t.

For example, when argon gas is supplied in cylinders in accordance with GOST 949 with a capacity of 40 dm 3, the volume of gas in the cylinder is:

at a pressure of 150 kgf/cm 2 at 20 °C

0.155 ´ 40 = 6.20 m3;

at a pressure of 200 kgf/cm 2 at 20 °C

0.206 ´ 40 = 8.24 m3.

(Changed edition, Amendment No. 2).

2. The amount of liquid argon in tanks is measured in tons or kilograms.

When converting the mass or volume of liquid argon to m 3 of gaseous argon under normal conditions, use the formulas given below.

Where m- mass of liquid argon, t;

V g - volume of liquid argon, dm 3.

1.662 - density of argon gas under normal conditions, kg/m3;

1.392 - density of liquid argon at normal pressure, kg/dm 3.

Coefficient ( K) to calculate the volume of gas in a cylinder in m 3 under normal conditions of 20 ° C and 101.3 kPa (760 mm Hg)

Gas temperature in the cylinder, °C

Excessive gas pressure in the cylinder, MPa (kgf/cm2)

APPENDIX 2

Information

The value of the coefficient K 2 to bring the volume of gas to normal conditions

Temperature, °C	Barometer readings, kPa (mm Hg)

APPLICATION2 .(Changed edition, Amendment No. 1).

APPENDIX 3. (Deleted, Amendment No. 2).

APPENDIX 4

Mandatory

DETERMINATION OF THE VOLUME FRACTION OF WATER VAPOR BY CONDENSATION METHOD

The volume fraction of water vapor is determined by condensation-type devices with a threshold sensitivity of no higher than 1.5 million -1 (ppm).

The relative error of the device should not exceed 10%.

The method is based on measuring the temperature of gas saturation with water vapor when dew appears on a cooled mirror surface.

The analysis is carried out according to the instructions supplied with the device.

The volume fraction of water vapor in accordance with the found saturation temperature is determined from the table. 1.

Table 1

Note. A volume fraction equal to 1 ppm corresponds to 1 ´ 10 -4%.

The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the relative discrepancy between which does not exceed the permissible discrepancy of 10%.

Permissible relative total error of the analysis result ±25% with confidence probability P = 0,95.

APPLICATION4 . (Changed edition, Amendment No. 3).

APPENDIX 5 DETERMINATION OF THE VOLUME FRACTION OF THE SUM OF CARBON-CONTAINING COMPOUNDS BY GAS CHROMATOGRAPHIC METHODS

A. Determination of the volume fraction of carbon dioxide obtained from the oxidation of carbon-containing compounds with copper oxide (according to clause 4.6.2 of this standard).

Chromatograph with a thermal conductivity detector with a sensitivity threshold for propane with a carrier gas (helium) not higher than 2 ´ 10 -5 mg/cm 3 and a gas chromatographic column 1.4 m long, with an internal diameter of 4 mm, filled with active carbon.

The concentrator is U-shaped. For production, a stainless steel tube 6 ´ 1 mm, 500 mm long, is taken. The concentrator is filled with crushed laboratory glass. A glass adapter (Fig. 1) with an extension and a plug for introducing the sample is attached to the concentrate.

The Dewar flask is glass, with a capacity of about 0.5 dm 3.

Gas drum meter (with liquid seal) type RG-700.

Auxiliary equipment for chromatographic analysis:

Glass adapter with stopper

a set of “Fizpribor” sieves or sieves of a similar type; medical injection syringes, Record type according to GOST 22967, capacity 2, 5, 10 cm 3;

mechanical stopwatch;

foam flow meter.

Liquid technical oxygen according to GOST 6331.

Purified gaseous helium with a volume fraction of carbon dioxide not exceeding 0.0001%.

Test gas mixture with a volume fraction of carbon dioxide in nitrogen of 0.50% - GSO No. 3765-87 according to the State Register.

Active carbon, grade SKT, fraction with particles 0.2 - 0.5 mm in size, dried at 150 °C for 4 hours.

Laboratory glass crushed in a porcelain mortar. The fraction with particles 0.2 - 0.5 mm in size is washed with hot distilled water and dried at 150 °C for 4 hours.

Copper mesh with a cell size of 0.1 - 0.15 mm or glass fiber according to GOST 10727.

2 . Preparing for analysis

The gas chromatography column is filled with active carbon; A layer of glass fiber 8 - 12 mm thick is laid on top of the coal layer. Then the column is fixed in the chromatograph thermostat and, without connecting to the detector, additionally dried at 150 °C for 8 hours in a flow of carrier gas at a flow rate of 30 cm 3 /min.

The concentrator is filled with crushed glass; A copper mesh is laid on top of the glass layer. The filled concentrator is purged with carrier gas for 3 hours.

The volume fraction of carbon dioxide is determined by the absolute calibration method, using a calibration gas mixture (CGM).

Before administering each dose, flush the concentrator with carrier gas (helium) for 1 minute. Then, stopping the helium supply, place the concentrator in a Dewar flask with liquid oxygen. After 3 minutes, the supply of carrier gas is turned on and a dose of PGS is introduced into its flow through an adapter. After 1 minute, replace the Dewar flask with liquid oxygen with a flask of water heated to 25 - 30 °C, and record a chromatogram of desorbed carbon dioxide.

Based on the PGS chromatograms, a calibration graph is constructed depending on the height of the carbon dioxide peak in millimeters, normalized to the sensitivity of the recorder (scale) M1, on the volume of carbon dioxide in each dose ( V 1) in milliliters, which is calculated by the formula

Where C st - volume fraction of carbon dioxide in ASG, %;

D st - dose of PGS, cm 3.

Graduation conditions. The temperature of the gas chromatographic column is 150 °C, the flow rate of carrier gas (helium) is 30 cm 3 /min. The detector supply current and the sensitivity of the recorder are established experimentally depending on the type of chromatograph.

The calibration is checked once a month using a gas mixture of carbon dioxide and nitrogen with a carbon dioxide volume fraction set at about 0.5%.

3 . Carrying out analysis

The chromatograph is connected to the network and switched to normal mode.

Place the concentrator in a Dewar flask with liquid oxygen. After 3 minutes, the analyzed gas is directed into the concentrate and 3 to 5 dm 3 of gas is passed through, depending on the measured volume fraction of carbon dioxide. The sample volume is measured using the gas meter readings.

Having completed sampling, flush the cooled concentrator with helium for 1 - 2 minutes, then replace the Dewar flask with liquid oxygen with a vessel of water heated to 25 - 30 °C, and record a chromatogram of desorbed carbon dioxide. The temperature of the gas chromatographic column, the flow rate of the carrier gas (helium) and the supply current of the detector must be identical to those adopted during calibration of the device. The recorder scale range is selected such that the carbon dioxide peak is maximum within the recorder chart strip.

4 . Processing the results

Based on the height of the carbon dioxide peak, normalized to the sensitivity of the M1 recorder, the volume of carbon dioxide in the argon sample is determined from the calibration graph and the volume fraction of carbon dioxide is calculated ( X) as a percentage according to the formula

Where V 1 - volume of carbon dioxide in the argon sample according to the calibration curve, cm 3;

V- volume of argon sample, cm 3.

B. Determination of the volume fraction of the sum of carbon-containing compounds with preliminary hydrogenation of carbon monoxide and carbon dioxide

1 . Equipment, materials and reagents

Chromatograph with a flame ionization detector, with a sensitivity threshold for propane not higher than 2.5 10 -8 mg/s.

The reactor is a stainless steel tube with a diameter of 3 to 5 mm, a length of 100 - 300 mm, filled with a catalyst, placed in an oven designed to be heated to a temperature of 500 °C.

Auxiliary equipment for chromatographic analysis according to claim 1.

Argon gas according to this standard, additionally purified from carbon-containing compounds to a volume fraction of no more than 0.0001%.

Technical fine-porous silica gel according to GOST 3956, fraction with particle size 0.5 - 1 mm.

Test gas mixtures with a volume fraction of methane in the air of 2.5 ppm and 7.5 ppm - GSO No. 3896-87; 10 million -1 - GSO No. 3897-87 according to the State Register.

A calibration gas mixture with a volume fraction of carbon dioxide in nitrogen of 50 ppm - GSO No. 3746-87 according to the State Register.

2 . Preparing for analysis

2.1. Install a gas chromatographic column (no more than 1 m long) not filled with adsorbent in the chromatograph.

The catalyst for filling the reactor is prepared as follows. Dry the silica gel at 150 - 180 °C for 4 hours in a drying cabinet, place it in a porcelain cup and fill it with a solution of nickel nitrate at the rate of: per 20 g of silica gel about 10 g of Ni(NO 3) 2 6H 2 O dissolved in water. Silica gel must be completely immersed in the solution. Excess solvent is evaporated. The mass is calcined at 600 - 800 °C until the release of nitrogen oxides stops, then cooled, the reactor is filled, connected to a chromatograph and nickel oxide is reduced to metallic nickel in a stream of hydrogen (flow rate 60 cm 3 /min) at 400 - 500 °C for 4 hours

The activity of the catalyst is checked using a test gas mixture of carbon dioxide in argon.

In a reactor connected via a tee to a gas chromatographic column (at the gas outlet), carbon dioxide is hydrogenated with hydrogen at 450 - 500 °C to methane. The methane peak is detected by a flame ionization detector. The volume fraction of carbon dioxide is determined from the height of the methane peak and compared with the nominal content of carbon dioxide in the mixture. The permissible discrepancy between the results is no more than 5%.

Additional purification of hydrogen in two columns, the first of which is filled with anhydrone, the second with dried and calcined synthetic zeolite. The second column is cooled with liquid nitrogen.

Additional purification of argon with copper oxide at 700 - 750 °C, followed by removal of moisture and carbon dioxide in two columns, the first of which is filled with anhydrone, the second with synthetic zeolite.

2.2. Chromatograph calibration

The calibration of the chromatographic installation (Fig. 3) is carried out using the absolute calibration method, using calibration mixtures. Based on the chromatograms of the calibration mixtures, a calibration graph is constructed of the dependence of the height of the methane peak, reduced to the sensitivity of the M1 recorder, in millimeters, on the volume fraction of methane in percent.

1 - a cylinder with the analyzed gas; 2 - a cylinder with carrier gas (nitrogen, argon or hydrogen); 3 - cylinder reducer; 4 - fine adjustment valve; 5 - dispenser; 6 - reactor; 7 - flame ionization detector; 8 - measuring device

The calibration is checked once every 3 months.

Graduation conditions. The carrier gas consumption of argon is 60 - 70 cm 3 /min, hydrogen 30 - 40 cm 3 /min, air 150 - 200 cm 3 /min, the dose of the calibration mixture is 1 - 2 cm 3. The sensitivity of the recorder is established experimentally, depending on the composition of the calibration mixture and the type of chromatograph.

3 . Carrying out analysis

3.1. A sample of the analyzed gas is introduced into the chromatograph using a dispenser. The reactor temperature, the flow rate of carrier gas, hydrogen and air, and the dose of the analyzed gas must be identical to those adopted during calibration of the device.

The sensitivity of the recorder is chosen such that the peak of the detected impurity is maximum within the chart strip of the recorder.

4 . Processing the results

4.1. Volume fraction of the sum of carbon-containing compounds in terms of CO 2 ( X 5) as a percentage is equal to the volume fraction of methane present in the analyzed gas and formed during the hydrogenation of carbon monoxide and dioxide, which is determined from the calibration graph based on the height of the methane peak, normalized to the sensitivity of the M1 recorder.

The result of the analysis is taken as the arithmetic mean of two parallel determinations, the permissible differences between which should not exceed 15% relative to the average result of the determined value with a confidence probability of 0.95.

APPLICATION5 . (Changed edition, Amendment No. 2).

(Changed edition, Amendment No. 2).

1 . DEVELOPED AND INTRODUCED by the USSR Ministry of Chemical Industry

2 . APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated November 23, 1979 No. 4496

Change No. 3 was adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 12 of November 21, 1997)

Registered by the Technical Secretariat of the IGU No. 2699

State name	Name of the national standardization body
The Republic of Azerbaijan	Azgosstandart
Republic of Armenia	Armgosstandard
Republic of Belarus	State Standard of Belarus
The Republic of Kazakhstan	Gosstandart of the Republic of Kazakhstan
Kyrgyz Republic	Kyrgyzstandard
The Republic of Moldova	Moldovastandard
Russian Federation	Gosstandart of Russia
The Republic of Tajikistan	Tajikgosstandart
Turkmenistan	Main State Inspectorate of Turkmenistan
	State Standard of Ukraine

4 . REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

			Number of paragraph, subparagraph, application
6 . EDITION (August 2005) with Amendments No. 1, 2, 3, approved in March 1985, November 1989, April 1998, (IUS 6-85, 2-90, 7-98)

GOST 10157-79

INTERSTATE STANDARD

ARGON GAS AND LIQUID

TECHNICAL CONDITIONS

IPC PUBLISHING HOUSE OF STANDARDS

Moscow

INTERSTATE STANDARD

Date of introduction 01.07.80

Formula Ar.

Atomic mass (according to international atomic masses 1985) - 39.948.

(Changed edition, Amendment No. 1, 2).

1. TECHNICAL REQUIREMENTS

1.1. Gaseous and liquid argon must be manufactured in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner.

1.2. In terms of physical and chemical parameters, gaseous and liquid argon must comply with the standards specified in table. 1.

Table 1

Indicator name	Norm
Indicator name	Top grade	First grade
1. Volume fraction of argon, %, not less
2. Volume fraction of oxygen, %, no more
3. Volume fraction of nitrogen, %, no more
4. Volume fraction of water vapor, %, no more, which corresponds to the temperature of saturation of argon with water vapor at a pressure of 101.3 kPa (760 mm Hg), °C, no more


5. Volume fraction of the sum of carbon-containing compounds in terms of CO 2,%, no more

Notes:

2. The standards for liquid argon indicated in the table correspond to the indicators for gaseous argon obtained by complete evaporation of a sample of liquid argon.

3. It is allowed to reduce the amount of liquid argon due to its evaporation during transportation and storage by no more than 10%.

1.3. NCP codes for gaseous and liquid argon are given in table. 2.

table 2

2. SAFETY REQUIREMENTS

2.1; 2.2. (Changed edition, Amendment No. 2).

2.6. When working in an argon atmosphere, it is necessary to use an insulating oxygen device or a hose gas mask.

3. ACCEPTANCE RULES

3.1. Gaseous and liquid argon are taken in batches. A batch is considered to be any quantity of a product that is uniform in terms of quality and documented in one quality document.

Each batch of liquid and gaseous argon must be accompanied by a quality document containing the following data:

name of the manufacturer and its trademark;

name of the product, its grade;

date of manufacture;

batch number, cylinder number (for argon gas);

volume of argon gas in cubic meters and mass of liquid argon in tons or kilograms (see Appendix 1);

results of analyzes performed or confirmation of product compliance with the requirements of this standard;

designation of this standard;

a type of hydrogen used to purify raw argon.

(Changed edition, Amendment No. 2).

The volume fraction of the sum of carbon-containing compounds is determined in samples taken every 8 hours from the common pipeline of argon gas supplied to the collectors. If unsatisfactory analysis results are obtained, repeated analyzes are carried out, selected from 2% of cylinders filled within 8 hours. The results of repeated analyzes apply to all cylinders filled during the specified period of time.

To control the argon pressure in filled cylinders, 10% of the cylinders from the shift output are selected.

(Changed edition, Amendment No. 1, 2, 3).

3.4. To control the quality of argon gas transported in auto-recipients, a sample is taken from each auto-recipient.

GOST 10157 79 argon dissolved and gaseous. Determination of the volume fraction of water vapor by the condensation method

H,

s", o s,

1. TECHNICAL REQUIREMENTS

2. SAFETY REQUIREMENTS

3. ACCEPTANCE RULES

4. METHODS OF ANALYSIS

5. PACKAGING, LABELING, TRANSPORTATION AND STORAGE

6. MANUFACTURER WARRANTY

ANNEX 1

APPENDIX 2

APPENDIX 4

APPENDIX 5

1. TECHNICAL REQUIREMENTS

2. SAFETY REQUIREMENTS

3. ACCEPTANCE RULES

4. METHODS OF ANALYSIS

5. PACKAGING, LABELING, TRANSPORTATION AND STORAGE

6. MANUFACTURER WARRANTY

ANNEX 1

CALCULATION OF THE AMOUNT OF GASEOUS AND LIQUID ARGON

APPENDIX 2

The value of the coefficient K 2 to bring the volume of gas to normal conditions

APPENDIX 4

DETERMINATION OF THE VOLUME FRACTION OF WATER VAPOR BY CONDENSATION METHOD

APPENDIX 5

DETERMINATION OF THE VOLUME FRACTION OF THE SUM OF CARBON-CONTAINING COMPOUNDS BY GAS CHROMATOGRAPHIC METHODS

1. TECHNICAL REQUIREMENTS

2. SAFETY REQUIREMENTS

3. ACCEPTANCE RULES

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