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1.1 This practice describes the techniques for planning, conducting, analyzing, and treating the results of an interlaboratory study (ILS) of a test method. The statistical techniques described in this practice provide adequate information for formulating the precision statement of a test method.

1.2 This practice does not concern itself with the development of test methods but rather with gathering the information needed for a test method precision statement after the development stage has been successfully completed. The data obtained in the interlaboratory study may indicate, however, that further effort is needed to improve the test method.

1.3 Since the primary purpose of this practice is the development of the information needed for a precision statement, the experimental design in this practice may not be optimum for evaluating materials, apparatus, or individual laboratories.

1.4 Field of ApplicationThis practice is concerned exclusively with test methods which yield a single numerical figure as the test result, although the single figure may be the outcome of a calculation from a set of measurements.

1.4.1 This practice does not cover methods in which the measurement is a categorization, such as a go-no-go allocation (two categories) or a sorting scheme into two or more categories. For practical purposes, the discontinuous nature of measurements of these types may be ignored when a test result is defined as an average of several individual measurements. Then, this practice may be applicable, but caution is required and a statistician should be consulted.

1.5 The information in this practice is arranged as follows:

Section
Scope 1
Referenced Documents 2
Terminology 3
Summary of Practice 4
Significance and Use 5
Planning the Interlaboratory Study (ILS)
ILS Membership 6
Basic Design 7
Test Method 8
Laboratories 9
Section
Materials 10
Number of Test Results per Material 11
Protocol 12
Conducting the Testing Phase of the ILS
Pilot Run 13
Full Scale Run 14
Section
Calculation and Display of Statistics
Calculation of the Statistics 15
Tabular and Graphical Display of Statistics 16
Data Consistency
Flagging Inconsistent Results 17
Investigation 18
Task Group Actions 19
Examples of Interlaboratory Studies 20
Precision Statement Information
Repeatability and Reproducibility 21
Appendixes
Theoretical Considerations A1
Index to Selected Terms A2
References
Tables and Figures
Tables Table
Glucose in Serum Example 14 & 67
Pentosans in Pulp Example 811
Critical Values of Consistency Statistics, h and k 5
Figures Fig.
Glucose in Serum Example 15
Pentosans in Pulp Example 610

1.6 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems 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.

Product Details

Published:
09/01/2009
Number of Pages:
23
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1 file , 260 KB
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