GB/T 6683.1-2021Petroleum and related products - Precision of measurement methods and results - Part 1: Determination of precision data in relation to methods of test (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1.Structure and Drafting Rules of Standardization Documents"

Drafting.

This document is the first part of GB/T 6683 "Measurement Methods and Precision of Results for Petroleum and Related Products". GB/T 6683 has

The following sections were released.

---Part 1.Determination of the precision data of the test method.

This document replaces GB/T 6683-1997 "Precision Data Determination Method for Petroleum Products Test Methods", and is consistent with GB/T 6683-1997

In addition to structural adjustments and editorial changes, the main technical changes are as follows.

a) Added and changed some terms and definitions (see Chapter 3, Chapter 3 of the.1997 edition);

b) Preliminary test procedures have been added (see 4.3);

c) Increased the parameter leverage ratio of the inspected samples (see 4.4);

d) The method of determining the number of laboratories and the number of samples has been changed (see 4.4, 4.3 in the.1997 edition);

e) The specific requirements for performing inter-laboratory research have been changed (see 4.5, 4.4 and 4.5 of the.1997 edition);

f) Added flow chart 1 (see 5.1) showing the procedure of transformation and outlier detection;

g) The technology "Generalized Extreme Average Deviation (GESD)" (see 5.2), which is used for the results of the pre-screening test, has been added;

h) Added the requirements and examples of whether data transformation is required and whether the transformation is successful or not (see 5.3.1);

i) A description of outliers has been added (see 5.3.2);

j) Added the requirement to check whether the used transformation is valid after discarding the outlier data (see 5.6);

k) Added the requirements, methods and examples of selected transformation confirmation (see 5.7);

l) The expression including the expectation of the mean square of the estimated value has been changed (see 6.3.2, 6.2.2 of the.1997 edition);

m) Added suggestions for optimizing the test method when the degree of freedom of reproducibility is less than 30 (see 6.3.3.2);

n) The precision expression method has been changed (see 6.4, 6.3 of the.1997 edition);

o) The instructions for determining the number of samples have been added as Appendix B;

p) Changed Appendix C on data tables and inspections (see Appendix C, Appendix A of the.1997 edition);

q) Added a description of GESD technology as Appendix D;

r) The calculation of the critical value of the normal distribution has been added (see E.8 in Appendix E);

s) Appendix F of the association type and transformation has been changed (see Appendix F, Appendix C of the.1997 edition);

t) Added the description of weighted linear regression analysis as Appendix G;

u) The method of using different transformations for repeatability and reproducibility has been added as Appendix H.

This document uses the redrafting method to modify and adopt ISO 4259-1.2017 "Petroleum and Related Products Measurement Methods and Results Precision No.

Part 1.Determination of the precision data of the test method".

Compared with ISO 4259-1.2017, this document has made the following structural adjustments.

---Adjusted the number and order of appendices;

---Move the calculation example content in Appendix D into 5.3~6.3;

--- Move the content of F.3 into Appendix G;

--- Move the content of F.4 into 5.3.1.

The main technical differences between this document and ISO 4259-1.2017 and the reasons are as follows.

---Regarding normative reference documents, this document has made adjustments with technical differences to adapt to my country's technical conditions and adjustments.

The situation is collectively reflected in Chapter 2 "Normative Reference Documents", and the specific adjustments are as follows.

* Replace ISO 5725-2.1994 (see 5.3.1) with GB/T 6379.2 which is equivalent to the international standard;

* Added reference to GB/T 8170 (see H.5.1).

--- Increase the repeatability and reproducibility of using different transformation methods to meet the requirements of use.

---The terms 3.6 and 3.10 that are not used in the text in ISO 4259-1.2017 are deleted.

---Deleted ISO 4259-1.2017 6.5 on the scope of the test method to adapt to the situation in my country.

---Deleted ISO 4259-1.2017 6.6 on the test method report limit description, in order to adapt to my country's use.

---Deleted the description of the R/r ratio in Chapter 7 in ISO 4259-1.2017 to adapt to the situation in my country.

---The introduction of symbols in ISO 4259-1.2017 C.1 was deleted to meet the requirements of GB/T 1.1.

--- Deleted the content about amendments in Appendix G of ISO 4259-1.2017.

The following editorial changes have been made to this document.

---Incorporated the amendments of ISO 4259-1.2017/Amd1.2019 and ISO 4259-1.2017/Amd2.2020, which are involved

The terms of has been marked by a vertical double line (||) on the outer margin of the page;

---Changed Figure 1 in 5.3.1 to reflect the technical differences between this document and ISO 4259-1.2017;

---Changed the expression in 5.3.3 to conform to the Chinese expression habits;

---Changed the expression in 5.3.4 to conform to the Chinese expression habits;

---Changed the expression in 5.4 to conform to the Chinese expression habits;

---Change the symbol K in 6.3.2 (change to J) to avoid duplication with K in 5.3.1 formula (5);

--- Deleted the formulas and chapters in Table I.1 to avoid duplication.

Introduction

In order to carry out quality control and check the conformity of products with specifications, it is necessary to use standard test methods to evaluate the properties of petroleum products. By specifying

In the same or different methods, two or more measurements of the same property of a specific sample often fail to obtain completely consistent results. because

Therefore, it is necessary to estimate the precision of the test method based on statistical principles, that is, the expected agreement between two or more results under a specified state.

Objective measurement of degree. This document gives the procedure for determining the precision of the test method and the application of the precision data. GB/T 6683 is proposed to consist of five

Partial composition.

---Part 1.Determination of the precision data of the test method. The purpose is to establish the method of designing inter-laboratory research (ILS), and adopt

Use this study to estimate the calculation method of the precision of the test method.

---Part 2.Interpretation and application of test method precision data. The purpose is to establish. when the nature is determined by a specific test method

The method of setting the property specification limit based on the precision of the test method, and when the supplier and the consignee obtain inconsistent results

Judgment of the conformity status of the case.

---Part 3.Monitoring and confirmation of the precision data of the test method. The purpose is to establish the precision of daily monitoring test methods

The method of comparing the precision with the published precision in the standard test method.

---Part 4.Laboratory verification that the test method standards are in a statistically controlled state. The purpose is to determine the use of statistical control

Figure, a method to confirm whether a single laboratory is under control when implementing test method standards.

---Part 5.Evaluation of the relative deviation between different methods of measuring the same characteristic. The purpose is to establish the

The statistical research method of relative deviation, and the determination of the functional relationship between relative deviations.

Petroleum and related products measurement methods and precision of results

Part 1.Determination of the precision data of the test method

1 Scope

This document describes the method of designing an inter-laboratory study (ILS) and the calculation method used to estimate the precision of the test method using the study.

This document specifies the steps of the ILS plan (Chapter 4) to determine the precision of the test method, as well as the calculation of the precision based on the results of the study.

Density method (Chapter 5 and Chapter 6).

The procedures specified in this document apply to homogeneous petroleum and related products. The procedures specified in this document can be applied to other types of homogeneous production

Care must be taken when applying to products whose uniformity has yet to be verified.

2 Normative references

The content of the following documents constitutes an indispensable clause of this document through normative references in the text. Among them, dated quotations

Only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to

This document.

GB/T 6379.2 Accuracy of measurement methods and results (accuracy and precision) Part 2.Determine the repeatability of standard measurement methods

Basic methods of performance and reproducibility (GB/T 6379.2-2004, ISO 5725-2.1994, IDT)

GB/T 8170 Numerical rounding rules and the expression and determination of limit values

3 Terms and definitions

The following terms and definitions apply to this document.

3.1

Analysis of variance; ANOVA

A technique for decomposing the total variation of the response variable into several meaningful components to determine the source of the variation.

[Source. GB/T 3358.3-2009, 3.4, with modification]

3.2

Accepted reference value acceptedreference value; ARV

The agreed standard values used for comparison include.

a) Theoretical or determined value based on scientific principles;

b) The designated value or certified value based on the experimental work of some countries or international organizations;

c) According to the agreed value or certification value in the cooperative experimental work under the auspices of a scientific or engineering organization;

d) When a), b), and c) cannot be obtained, the measurable expectation is used, that is, the average value of the measurement population is specified.

Note. For example, results obtained by inter-laboratory research.

[Source. GB/T 3358.2-2009, 3.2.7, with modification]

3.3

Betweenlaboratoryvariance

The components of the total variance can be attributed to the differences in the mean values of different laboratories.

Note 1.When comparing the results obtained by multiple laboratories, the dispersion is usually wider than the results obtained by a single laboratory for the same number of tests.