GOST 30609-98

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  ГОСТ 30609-98

GOST 30609−98 Brass foundries. XRF technology

GOST 30609−98
Group B59

INTERSTATE STANDARD

BRASS CASTING

XRF technology

Brass castings. Method of X-ray fluorescent analysis

ISS 77.120.10*
AXTU 1709
____________________
* In the index «National standards», 2008
ISS 77.120.10 and 77.120.60. — Note the manufacturer’s database.

Date of introduction 2001−07−01

Preface

1 DEVELOPED by the Interstate technical Committee for standardization MTK 107, Donetsk state Institute of non-ferrous metals (Danism)

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. 14 dated November 12, 1998)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated December 19, 2000 N 384-St inter-state standard GOST 30609−98 introduced directly as state standard of the Russian Federation from July 1, 2001

4 INTRODUCED FOR THE FIRST TIME

1 Scope

This standard specifies x-ray fluorescence method for the quantitative chemical analysis of samples of cast brass on the contents of elements are given in table 1.

Table 1 — Range of mass fraction of detectable elements

2 Normative references

The present standard features references to the following standards:

GOST 8.315−97 State system for ensuring the uniformity of measurements. Standard samples of composition and properties of substances and materials. The main provisions of the

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

GOST 12.1.019−79 System of standards of occupational safety. Electrical safety. General requirements and nomenclature of types of protection

GOST 12.1.038−82 standards System of labor safety. Electrical safety. The maximum permissible values of the touch voltage and currents

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

GOST 18300−87 ethyl rectified technical. Specifications

GOST 24231−80 non-ferrous metals and alloys. General requirements to selection and preparation of samples for chemical analysis

GOST 25086−87 non-ferrous metals and their alloys. General requirements for methods of analysis

3 the essence of the method

Method is based on the intensity of the characteristic fluorescence lines of the element from its mass fraction in the sample. Excited by the primary x-ray characteristic radiation of elements in the sample is decomposed into a spectrum with subsequent measurement of analytical signal and determining the mass fraction of the element using the calibration parameters.

4 Equipment and materials

Scanning or multi-channel x-ray fluorescence spectrometers.

The lathe or other equipment for the preparation of samples for analysis.

Argon-methane mixture (for spectrometers using flow-proportional counters).

The technical rectified ethyl alcohol according to GOST 18300.

Standard samples (SS) according to GOST 8.315.

Allowed to use other equipment and materials ensuring the accuracy of the analysis required by this standard.

5 Preparing for analysis

5.1 General requirements — according to GOST 25086.

5.2 Selection and preparation of samples for analysis is carried out in accordance with GOST 24231 and normative documents regulating the requirements to the quality of cast brass.

5.3 Analyze the surface of the samples sharpened on a lathe and rubbed with alcohol. Sharpened the plane of the sample should be flat, smooth, without shrink holes, pores, cracks, slag and nonmetallic inclusions, to avoid distortion of results due to possible scattering of radiation in the depressions and grooves. Preparation of the analyzed surface is performed directly before analysis.

5.4 the Sample must completely cover the hole of the receiver samples (cassette, camera, or cell). If the analyzed sample does not cover the hole, apply the device in the form specifically designed for this purpose, the metal diaphragm limiting surface exposure.

5.5 the Graduation of the spectrometer is carried out on the composition of cast brass. Processing of irradiated surfaces and their area surface exposure must be identical to the sample.

5.6 Calibration characteristics established taking into account the influence of the chemical composition and physico-chemical properties and a test portion, expressed in the form of the relation equation, graphs, or tables.

For the spectrometer, interfaced with a computer, the procedure of calibration is determined by the software.

5.7 Preparation of spectrometer measurements carried out according to instructions for its maintenance and operation.

The conditions of analysis are given in Appendix A.

Allowed to use other conditions analysis and spectral lines, ensuring the accuracy of the analysis required by this standard.

6 analysis and processing of results

6.1 the Analyzed sample is placed in the receiver of the sample, paying particular attention to the absence of distortions. Further loop analysis occurs automatically.

6.2 Analysis of samples is performed in two parallel determinations. For the results of parallel determination to accept the registration result for a single exposure (accumulation time) of the analytical signal, expressed in terms of the mass fraction of the element, followed by the sample under irradiation.

6.3 differences between the results of parallel measurements of the analytical signal, expressed in units of mass fraction element must not exceed the permissible confidence probability of 0.95. The permissible variance is calculated by the formula

, (1)

where 2,77 — critical value of the ratio of the magnitude of the results of two parallel measurements to the average standard deviation confidence probability of 0.95;

 — the relative standard deviation characterizing the convergence of the results of parallel measurements. The values given in table 2;

 — the arithmetic mean of the results of parallel measurements.


Table 2 — Norm accuracy of the identified elements

6.4 the result of analysis should be the arithmetic mean of two parallel definitions, to meet the requirements of 6.3.

6.5 measurement Results issued in the form of a report. The report must contain:

— data necessary to characterize the samples;

— the results of the analysis, indicating their error;

— reference to this standard;

— a description of any abnormalities seen in the analysis;

— indication for conducting the analysis of any operations not specified in this standard.

7 Control of accuracy of analysis results

7.1 Control of accuracy of analysis results is carried out using the composition or of samples the homogeneity thereof. The frequency control reglamentario given the stability of the calibration parameters for each specific x-ray fluorescence spectrometer.

7.2 an Extraordinary control of accuracy of analysis results is carried out after repair, prevention of the spectrometer or changes in the terms of analysis.

7.3 Control the convergence of the results of parallel measurements of mass fractions of elements and samples is carried out in accordance with 6.3.

7.4 Control of reproducibility of results of analysis performed by defining the mass fraction of elements in SB, and (or) previously analyzed samples.

Discrepancies in the results of primary and repeated analyses of the same sample or must not exceed the permissible discrepancy (confidence probability 0,95) calculated according to the formula

, (2)

where 2,77 — critical value of the ratio of the magnitude of the two results of the analysis to their average standard deviation confidence probability of 0.95;

 — the relative standard deviation characterizing the reproducibility of the results. The values given in table 2;

 — the arithmetic mean of the results of the initial and re-analysis or certified value of the mass fraction of the element.

7.5 If the verification of the analysis results using the differences between the reproduced and certified mass fractions of the element WITH no more than 0.4 .

7.6 in case of control of correctness by selectively comparing the results of XRF analysis of samples with the result of the analysis of the same samples obtained on other standardized or certified methods shall be a condition

, (3)

where is the other acceptable standardized or certified methods the discrepancy between the results of the analysis of the same sample.

7.7 If the discrepancy between the results of parallel measurements or differences between the results of the analysis at 7.4−7.6 exceeds the permissible value, the analysis is repeated.

If and when re-analysis of the divergence exceeds the allowable value, the results of the analysis, recognize the wrong and stop measuring to ascertain and eliminate the causes of violations of the normal course of analysis.

7.8 the results of the analysis of several samples taken from the same batch of alloy, can only be interpreted taking into account the heterogeneity of the party, errors in sampling, etc.

8 security Requirements

8.1 All electrical installations and electrical equipment used in the process of spectral analysis shall conform to the requirements of GOST 12.2.007.0 and electrical codes.

Operation of electrical installations and electrical appliances must be in accordance with the requirements of GOST 12.1.019, GOST 12.1.038, rules of technical operation of electrical installations and safety rules at operation of electrical installations approved by the relevant organizations the power company.

8.2 When working with radioactive sources shall adhere to the requirements of sanitary rules and norms in accordance with [1] and [2].

8.3 fire safety Requirements should correspond to GOST 12.1.004.

9 qualifications of the operator

To work on x-ray fluorescence spectrometer allowed laboratory technicians x-ray analysis at least 4-th level of qualification.

Annex a (recommended). The conditions of analysis

APPENDIX A
(recommended)

Table A. 1 — requirements analysis for various types of x-ray fluorescence spectrometers

Table A. 2 — Length of spectral lines

ANNEX B (reference). Bibliography

APPENDIX B
(reference)

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* On the territory of the Russian Federation there are SP 2.6.1.758−99. — Note the manufacturer’s database.