Significance and Use
The purpose of this practice is to evaluate the homogeneity of a lot of material selected as a candidate for development as a reference material or certified reference material, or for a L/B selected for some other purpose (see Appendix X1-Appendix X4 for examples).
This practice is applicable to the testing of samples taken at various stages during production. For example, continuous cast materials, ingots, rolled bars, wire, etc., could be sampled at various stages during the production process and tested.
1.1 This practice is suitable for testing the homogeneity of a metal lot or batch (L/B) in solid form by spark atomic emission spectrometry (Spark-AES). It is compliant with ISO Guide 35—Certification of Reference Materials: General and Statistical Principles. It is primarily intended for use in the development of reference materials but may be used in any other application where a L/B is to be tested for homogeneity. It is designed to provide a combined study of within-unit and between-unit homogeneity of such a L/B.
1.2 This practice is designed primarily to test for elemental homogeneity of a metal L/B by Spark-AES. However, it can be adapted for use with other instrumental techniques such as X-ray fluorescence spectrometry (XRF) or atomic absorption spectrometry (AAS).
Note 1—This practice is not limited to elemental analysis or techniques. This practice can be applied to any property that can be measured, for example, the property of hardness as measured by the Rockwell technique.
1.3 The criteria for acceptance of the test specimens must be previously determined. That is, the maximum acceptable level of heterogeneity must be determined on the basis of the intended use of the L/B.
1.4 It is assumed that the analyst is trained in Spark-AES techniques including the specimen preparation procedures needed to make specimens ready for measurements. It is further assumed that the analyst is versed in and has access to computer-based data capture and analysis. The methodology of this practice is best utilized in a computer based spreadsheet.
1.5 This practice can be applied to one or more elements in a specimen provided the signal-to-background ratio is not a limiting factor.
1.6 This practice includes methods to correct for systematic drift of the instrument with time. (Warning—If drift occurs, erroneous conclusions will be obtained from the data analysis.)
1.7 This practice also includes methods to refine estimates of composition and uncertainty through the use of a type standard or multiple calibrants.
1.8 It further provides a means of reducing a nonhomogeneous set to a homogeneous subset.
1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E178 Practice for Dealing With Outlying Observations
E634 Practice for Sampling of Zinc and Zinc Alloys by Spark Atomic Emission Spectrometry
E716 Practices for Sampling and Sample Preparation of Aluminum and Aluminum Alloys for Determination of Chemical Composition by Spectrochemical Analysis
E1329 Practice for Verification and Use of Control Charts in Spectrochemical Analysis
E1601 Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method
E1806 Practice for Sampling Steel and Iron for Determination of Chemical Composition
ISOGuide35 Certification of Reference Materials: General and Statistical Principles
atomic emission spectroscopy; homogeneity; reference materials; Flame emission spectroscopy; Homogeneity; Instrumental measurement--spectrochemical; Metals and metallic materials; Optical emission spectrometry (OES); Reference samples/specimens; Spectral data--metals/alloys; Spectrochemical analysis; Spectroscopy--emission; Spectroscopy--X-ray emission; X-ray emission spectrometry;
ICS Number Code 77.040.99 (Other methods of testing metals)
ASTM International is a member of CrossRef.
Citing ASTM Standards
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