GB/T 19494.3-2023 English PDFUS$969.00 · In stock
Delivery: <= 7 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 19494.3-2023: [Including 2025XG1] Mechanical sampling of coal - Part 3: Determination of precision and bias test Status: Valid GB/T 19494.3: Historical versions
Basic dataStandard ID: GB/T 19494.3-2023 (GB/T19494.3-2023)Description (Translated English): [Including 2025XG1] Mechanical sampling of coal - Part 3: Determination of precision and bias test Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: D21 Classification of International Standard: 73.040 Word Count Estimation: 47,469 Date of Issue: 2023-11-27 Date of Implementation: 2024-03-01 Older Standard (superseded by this standard): GB/T 19494.3-2004 Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration GB/T 19494.3-2023: [Including 2025XG1] Mechanical sampling of coal - Part 3: Determination of precision and bias test---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. ICS 73:040 CCSD21 National Standards of People's Republic of China Replace GB/T 19494:3-2004 Mechanized sampling of coal Part 3: Determination of precision and bias testing (ISO 13909-7:2016,Hardcoalandcoke-Mechanicalsampling- andtesting;ISO 13909-8:2016,Hardcoalandcoke-Mechanicalsampling- Published on 2023-11-27 and implemented on 2024-03-01 State Administration for Market Regulation Released by the National Standardization Administration Committee Table of contentsPrefaceⅠ Introduction II 1 Scope 1 2 Normative references 1 3 Terms and Definitions 1 4 Sampling, sample preparation and assay precision determination 1 5 Bias test methods 20 Appendix A (informative) Bias test calculation example 32 Reference 42ForewordThis document complies with the provisions of GB/T 1:1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting: This document is Part 3 of GB/T 19494 "Mechanized Sampling of Coal": GB/T 19494 has published the following parts: ---Part 1: Sampling methods; ---Part 2: Preparation of coal samples; ---Part 3: Precision determination and bias testing: This document replaces GB/T 19494:3-2004 "Mechanized Coal Sampling Part 3: Precision Determination and Bias Test" and is consistent with Compared with GB/T 19494:3-2004, in addition to structural adjustments and editorial changes, the main technical changes are as follows: a) Deleted the content about the precision of discontinuous sampling (see 4:2:3 of the:2004 version); b) Changed the expression of precision range estimation (see 4:4:1:2:2, 4:4:1:2:2 of the:2004 version); c) Added special precautions for moisture test samples (see 5:2:2); d) Added precautions when preparing reference samples (see 5:4:4); e) Deletion of the decision on maximum allowable bias (see 5:7 of the:2004 edition); f) Increased the number of bias test sample pairs (see 5:7); g) Added the method for determining the acceptable bias range (see 5:8); h) Changed the composition description of the bias test sample pair (see 5:9:1, 5:8:1 of the:2004 version); i) Changed the formulation of detailed test procedures for bias tests (see 5:10:1, 5:9:1 of the:2004 version); j) Changed the methods of bias test, statistical analysis and result evaluation (see 5:11:1~5:11:4, 5:10:1~ of the:2004 version 5:10:7): This document refers to ISO 13909-7:2016 "Mechanized sampling of hard coal and coke Part 7: Sampling, sample preparation and test precision measurement Drafting of "Determined Method" and ISO 13909-8:2016 "Mechanized Sampling of Hard Coal and Coke Part 8: Bias Test Method", degree of consistency is not equivalent: Please note that some content in this document may be subject to patents: The publisher of this document assumes no responsibility for identifying patents: This document is proposed by the China Coal Industry Association: This document is under the jurisdiction of the National Coal Standardization Technical Committee (SAC/TC42): This document was drafted by: Coal Science and Technology Research Institute Co:, Ltd: The main drafters of this document: Pi Zhongyuan, Han Liting, Yang Huayu, Sui Yan: This document was first published in:2004 and this is the first revision:IntroductionGB/T 19494 aims to establish guidelines that are generally applicable to mechanized sampling of coal and provide guidance for the sampling process and production of mechanized coal sampling systems: Establish an operable, traceable, and verifiable method for sampling, precision measurement, and bias testing, which consists of three parts: ---Part 1: Sampling methods; ---Part 2: Preparation of coal samples; ---Part 3: Precision determination and bias testing: In order to standardize the mechanized sampling of coal, my country issued the GB/T 19494 series of standards for the first time in:2004, which stipulated the Sampling, sample preparation, precision determination and bias test methods for mechanized sampling systems: GB/T 19494 series of standards have been released and implemented for nearly 20 years During this period, the application of mechanized coal sampling became more and more widespread, and its standardization received more and more attention: Found during the implementation of the standard Some problems have been solved, such as in the precision measurement, the sampling system performance test unit gave an incorrect sampling precision due to the deviation in its understanding of the standard: degree of confidence range; for example, in a bias test, in order to make the bias test result qualified, the maximum allowable bias value is automatically enlarged; the above phenomenon causes the Misleading parties involved in the use of sampling systems: In view of this, it is indeed necessary to revise and improve GB/T 19494 to continuously adapt to new developments in related technologies at home and abroad: Changes, as well as new demands for the development of industrial practice, ensure the scientific nature of the national standard system supporting mechanized sampling of coal: by establishing more Strict method rules provide users with evidence to rely on, thereby improving the quality and application efficiency of coal mechanized sampling, and better promoting trade and Technology Exchange: Mechanized sampling of coal Part 3: Determination of precision and bias testing1 ScopeThis document specifies the mechanized coal sampling, sample preparation and assay precision determination and bias test methods: This document applies to precision measurement and bias testing of coal mechanized sampling:2 Normative reference documentsThe contents of the following documents constitute essential provisions of this document through normative references in the text: Among them, the dated quotations For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document: GB/T 19494:1 Mechanized coal sampling Part 1: Sampling methods GB/T 19494:2 Mechanized sampling of coal Part 2: Preparation of coal samples3 Terms and definitionsThe terms and definitions defined in GB/T 19494:1 and GB/T 19494:2 apply to this document: 4 Sampling, sample preparation and assay precision determination 4:1 Overview When designing a sampling plan with a precision that meets the requirements, there must be a correlation between precision and coal characteristics and sampling characteristics: The main relevant factors are the variability of coal (i:e: sub-sample variance), sample preparation and test errors, the number of sub-samples and total samples, and the quality of the samples: There are several methods for estimating precision, depending on the purpose of sampling and the sampling plan and equipment used: There are two situations: a) For existing sampling systems, the purpose of the test is to check whether the sampling plan can actually achieve the desired precision: If not, then It needs to be improved until the precision reaches the desired value: The most rigorous method for verifying the precision of a routine sampling plan is Double sampling method for multiple sampling units (see 4:4:1): b) For a specific batch of coal, the purpose of the test is to estimate the achievable precision from actual test results: At this time, the best way It is a multiple sampling method (see 4:4:2): The precision calculation formula given in this document is based on the following assumptions: the quality change of the sampled coal is random; the quality observation value is a normal distribution cloth: Although these two assumptions are not very accurate for some coal quality parameters, the degree of deviation between the actual state and the assumed state has a significant impact on the precision verification formula: There is no practical impact on the validity of the equation because the statistical methods used in this document are not very sensitive to non-normal distributions: Coal quality often has a certain serial correlation, that is, adjacent coals tend to have similar compositions, and coals that are far apart tend to have similar compositions: Dissimilar composition: The primary sub-sample variance obtained from the experiment may be different from the actual one: Therefore, the primary sub-sample variance and the system Depending on the sample and assay variance, the precision estimate obtained will be different from what is actually achieved: ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 19494.3-2023_English be delivered?Answer: Upon your order, we will start to translate GB/T 19494.3-2023_English as soon as possible, and keep you informed of the progress. 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