GOST 22974.0-96

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  ГОСТ 22974.0-96

GOST 22974.0−96 fused welding Fluxes. General requirements for methods of analysis

GOST 22974.0−96

Group B09

INTERSTATE STANDARD

FUSED WELDING FLUXES

General requirements for methods of analysis

Melted welding fluxes.
General requirements for methods of analysis

ISS 77.040
AXTU 0809

Date of implementation 2000−01−01

Preface

1 DEVELOPED by the Interstate technical Committee for standardization MTK 72; the Institute of electric them. E. O. Paton of NAS of Ukraine

SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 9 dated April 12, 1996)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology, dated April 21, 1999 N 134 inter-state standard GOST 22974.0−96 introduced directly as state standard of the Russian Federation from January 1, 2000

4 REPLACE GOST 22974.0−85

1 Scope

This standard establishes General requirements for methods of chemical analysis of melted welding fluxes.

2 Normative references

The present standard features references to the following standards:

GOST 3−88 Gloves surgical rubber. Specifications

GOST 12.0.004−90 System of standards of occupational safety. Organization of training safety. General provisions

GOST 12.1.004−91 System safety standards. Fire safety. General requirements

GOST 12.1.005−88 standards System of labor safety. General hygiene requirements for working zone air

GOST 12.1.007−76 System of standards of occupational safety. Harmful substances. Classification and General safety requirements

GOST 12.1.010−76 System of standards of occupational safety. No danger of explosion. General requirements

GOST 12.2.007.0−75 System safety standards. Products electrical. General safety requirements

12.4.009 GOST-83 System of standards of occupational safety. Fire fighting equipment for protection of objects. Principal. The accommodation and service

GOST 12.4.013−85* the System of occupational safety standards. Glasses protective. General specifications
________________
* On the territory of the Russian Federation GOST R 12.4.013−97**.

** On the territory of the Russian Federation GOST R 12.4.230.1−2007. — Note the manufacturer’s database.

GOST 12.4.021−75 System safety standards. System ventilation. General requirements

GOST 12.4.023−84 System of standards of occupational safety. Protective face shields. General technical requirements and methods of control

GOST 12.4.029−76 special Aprons. Specifications

12.4.121 GOST-83 System of standards of occupational safety. Industrial filtering gas masks. Specifications

GOST 12.4.131−83 Bathrobes for women. Specifications

GOST 12.4.132−83 Robes for men. Specifications

GOST 1770−74 laboratory Glassware measuring glass. Cylinders, beakers, flasks, test tubes. Specifications

GOST 6563−75 technical articles made of noble metals and alloys. Specifications

GOST 6613−86 Grids wire woven with square cells. Specifications

GOST 6709−72 distilled Water. Specifications

GOST 9087−81 melted welding Fluxes. Specifications

GOST 9147−80 Glassware and equipment lab porcelain. Specifications

GOST 20010−93 Gloves technical. Specifications

GOST 21130−75 electrical Products. Clamps earthing and grounding. The design and dimensions

GOST 24104−88* laboratory Scales General purpose and model. General specifications
________________
* On the territory of the Russian Federation GOST 24104−2001. Here and further. — Note the manufacturer’s database.

GOST 25336−82 Glassware and equipment laboratory glass. The types, basic parameters and dimensions

GOST 29227−91 oils. Pipettes are graduated. Part 1. General requirements

GOST 29251−91 oils. Burette. Part 1. General requirements

3 General requirements

3.1 Sampling is carried out according to GOST 9087 with additions.

3.1.1 Sample weighing 150−200 g ground to pass through a sieve with mesh N 05 to GOST 6613, stir thoroughly and reduce kvantovanie to 25−30 g, again ground to pass through a sieve with mesh N 02 GOST 6613.

Take 10−15 g, atminciai from iron impurities, ground to a fine powder through the sieve N 0063 GOST 6613.

Laboratory the sample is dried in a drying Cabinet at a temperature of (100±5) °C for 1 h and stored in a desiccator according to GOST 25336 filled with calcium chloride, calcined at a temperature of 700−800 °C for 1 h.

3.1.2 Weighing of test portions, precipitation, crucibles carried out on laboratory scales General purpose according to GOST 24104 2nd accuracy class with the largest weighing limit of 200 g or any other balance with the characteristics that meet the metrological requirements.

3.1.3 Mass fraction of each component in the sample and the standard sample determined in two batches, with the mass fraction of component over 20% in three batches. Simultaneously with the tests in the same conditions by two (three) of the control expertise to make the result of the analysis corrections for contamination of reagents.

For the result of the analysis of the sample or the standard sample and take the arithmetic mean of the results of the two definitions given of the arithmetic mean of the two results in the reference experiment.

The numerical value of the result of the analysis should be terminated with a figure the same category as the corresponding error value .

Upon receipt of the results of the analysis that differ from the boundaries of the brand in less than 0.7 of the permissible differences for the respective concentration ranges, should re-analysis simultaneously with analysis of a standard sample. To control the error of the results of the analysis of the test sample at least once per shift under the same conditions analyze the standard sample in two batches.

The error analysis result (at p = 0.95) will not exceed the limit in % is given in the relevant standard methods of analysis of the mass fraction of the component when the following conditions are met:

the difference between the two (three) of the definitions shall not exceed (at p = 0.95), values (), % given in the relevant standard methods of analysis of the mass fraction of component;

— played in the standard sample, the value of the mass fraction of the component must not vary from certified more than acceptable at a confidence level of 0.85, the value in % is given in the relevant standard method of analysis of the mass fraction of the component.

If any of these conditions, a second analysis. If and when re-analysis of the requirements for the accuracy of the results is not performed, these results admit the infidels, the analysis is stopped until the identification and elimination of the causes of the disruption of the analysis.

The differences between the two average results of analysis, obtained under different conditions (for example, when the control intralaboratory reproducibility) shall not exceed (at p = 0.95) value , %, is given in the relevant standard methods of analysis of the mass fraction of the component.

Monitoring the error of the average result by the method of additions is carried out by calculation of the mass fraction of the analyte in the test material after adding an appropriate sample of pure metal or aliquote part of a standard solution of this component to the sample of analyte prior to analysis. The amount of additives is chosen so that the analytical signal of the designated component increased 1.5−2 times compared with the analytical signal of this component in the absence of additives. We should also maintain the optimal conditions of analysis provided by a particular standard on method of analysis. Carry out the determination of this component in the sample after the introduction of additives. The amount of additive is calculated as the difference between the found value of the mass fraction of the component in the sample with the additive and without the additive.

The error of the average result analysis will not exceed the limit , if the found value differs from the calculated Supplement, no more than , where and are taken from the relevant standard method of analysis for values of the mass fraction of the monitored component in the sample, respectively, with the additive and without additive.

Control of results accuracy analysis of synthetic mixtures is performed by reproducing the values of the mass fraction of the designated component is introduced into the mixture. Determination of the mass fraction of the monitored component in the synthetic mix is carried out simultaneously with the analysis of samples with the same number definitions established by the method of analysis.

The error of the result of the analysis will not exceed the limit , if the synthetic mixture the following conditions hold:

the difference between the two (three) of the definitions shall not exceed (at p = 0.95), values (), % given in the relevant standard methods of analysis of the mass fraction of component;

— played in the standard sample, the value of the mass fraction of the component must not vary from certified more than acceptable (at a confidence level of 0.85) value , %, is given in the relevant standard method of analysis of the mass fraction of component;

— played the value of the mass fraction of a component in synthetic mixtures differs from that introduced into the mixture is not more than the amount taken from the relevant standard methods

analysis.

3.1.4 For the preparation of aqueous solutions of reagents used distilled water according to GOST 6709 or deionized water quality is not below specified in the standard, if no other requirements in the standard methods of analysis.

3.1.5 In terms of the «diluted 1:1, 1:2», etc designations (1:1), (1:2) etc. the first digit represents the volumetric part of the dilute reagent (e.g. concentrated acids), the second volume of the solvent (e.g. water).

If the standard does not indicate the concentration of the acid or an aqueous solution of ammonia, then use concentrated acid or concentrated aqueous ammonia solution.

3.1.6 solution Concentration is expressed in units of measurement:

— mass concentration, g/DM; g/cm;

is the molar concentration of equivalent — mole/DM.

3.1.7 preparation of solutions and reagents and performing the analysis after each addition of reagents the solution was stirred.

3.1.8 For analysis is used:

cylinders, beakers, flasks and test tubes according to GOST 1770;

pipettes according to GOST 29227;

— burette according to GOST 29251;

— glassware and equipment glass according to GOST 25336;

— porcelain crucibles, boats, etc. according to GOST 9147;

— crucibles and cups made of platinum according to GOST 6563;

— reagents qualification not lower than «pure for analysis» (h. e. a.);

— other measuring instruments, equipment and other labware with the metrological and technical characteristics are not worse standardised.

3.1.9 In titrimetric analysis, the mass concentration of the titrated solution at the defined component set in three batches or aliquote parts of the original substance. The arithmetic average of the three obtained results are rounded to four significant digits.

The mass concentration of a standard solution prepared from metal or chemical substances establish not less than three batches of the starting material.

Allowed to set, the mass concentration of standard solutions for standard samples, if required by the standard for methods for the determination of the component.

3.1.10 the concept of «room temperature», «warm» or «hot» water (or solution) means that the fluid has a temperature of respectively 15−25 °C, 40−75 °C, more than 75 °C.

3.1.11 When using instrumental methods of analysis it is necessary to choose optimal conditions of measurement of the analytical signal provides the necessary sensitivity and accuracy depending on the method applied, the type of device, defined by the component and its mass fraction in the sample.

Calibration curve building in the system of rectangular coordinates: the x-axis postpone the numerical value of the mass concentration, mass fraction or component mass in a certain volume of the solution; on the axis of ordinates the value of the analytical signal, measured parameter or function from it.

Conditions of preparation of solutions for measuring the analytical signal and the method of constructing the calibration graph indicate the standard methods of determining the mass fraction of the component. Validation of calibration curve performed simultaneously with analysis in accordance with the requirements of the standard on methods of determining the mass fraction of the component. Allowed to apply the calibration function representing the equation of the calibration curve, and use the comparison method of the analytical signal of the sample with the analytical signal of standard solution defined by the component or the solution of a standard sample, if it is stipulated in standard methods for the determination of the mass fraction of the component.

3.1.12 For construction of the calibration graphs must be at least five calibration points, which are distributed evenly throughout the measurement range. Each of the points should be based on the average of the results of the two (three) definitions.

4 safety Requirements

4.1 Chemical analyses must be performed in accordance with the regulatory documents on safe conducting works in the chemical laboratory, duly approved.

4.2 Laboratory facilities which are used for the chemical analyses, should be equipped with exhaust ventilation in accordance with the requirements of GOST 12.4.021.

4.3 Requirements for fire safety when working in a chemical laboratory must meet the requirements of GOST 12.1.004.

4.4 Types of fire equipment and firefighting equipment must meet the requirements of GOST 12.4.009.

4.5 Fume hoods should be equipped with closed heating stoves and muffle furnaces.

4.6 For the preparation of flux analysis, atomic absorption units, a laboratory balance is necessary to have a separate room.

4.7 Electrical equipment and appliances must comply with the requirements of GOST 12.2.007.0, GOST 21130 and electrical codes.

4.8 acid vapors and dry dust alkalis and oxides are irritating to the respiratory tract and mucous membranes of the eyes and nose. Solutions and alkalis, when applied to the skin, causing severe burns. According to GOST 12.1.005 mineral acids (hydrochloric, nitric, sulfuric and hydrofluoric) and alkalis belong to the second class of danger. The maximum allowable concentration of these substances in the air of working zone shall conform to the requirements of GOST 12.1.005.

4.9 Control of content of harmful substances in the air of the working zone of production areas must be carried out in accordance with the requirements of GOST 12.1.007 and GOST 12.1.005.

4.10 Requirements when working with flammable and explosive gases must comply with GOST 12.1.010 and GOST 12.1.004 and safety rules in the gas sector.

4.11 When using gases in cylinders must comply with the rules for design and safe operation of vessels working under pressure.

4.12 Storage of reagents and other necessary materials shall conform to the requirements of normative documents regulating their storage.

4.13 Placing and storing chemical reagents and other materials used in the analysis and which are hazardous and harmful properties, and their use must meet the normative documentation on their production and application.

4.14 To work in the chemical laboratory is open to persons aged 18 years preliminary training in safe working practices in a chemistry laboratory and rules for the treatment of protective devices in accordance with GOST 12.0.004 and special safety record in the prescribed manner according to GOST 12.0.004.

4.15 depending on the performed analysis, working in a chemical laboratory should be provided with personal protective equipment (robes 12.4.131 according to GOST and GOST 12.4.132, rubber mittens according to GOST 20010, or GOST 3, the apron according to GOST 12.4.029, protective goggles according to GOST 12.4.013, protective shields according to GOST 12.4.023, gas masks according to GOST 12.4.121).