ASTM E691-05

    Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method


      Format Pages Price  
    PDF 23 $89.00   ADD TO CART

    Active (view current version of standard)

    Other Historical Standards

    Work Item(s) - proposed revisions of this standard

    ASTM License Agreement

    More E11.20 Standards Related Products


    1. Scope

    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.

    1.1.1 A computer software package for performing the calculations and producing the tables and graphs associated with Practice E 691. This software can be run on PC compatible computers, and hard copy tables and graphs can be printed on dot-matrix printers.

    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 Application—This 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 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.


    2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

    E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods

    E456 Terminology Relating to Quality and Statistics

    E1169 Practice for Conducting Ruggedness Tests

    E1402 Guide for Sampling Design

    E2282 Guide for Defining the Test Result of a Test Method


    UNSPSC Code

    UNSPSC Code


    Referencing This Standard
    Link Here
    Link to Active (This link will always route to the current Active version of the standard.)

    DOI: 10.1520/E0691-05

    Citation Format

    ASTM E691-05, Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method, ASTM International, West Conshohocken, PA, 2005, www.astm.org

    Back to Top