ASTM_D_4356_-_84_2002.pdf

Designation:D 4356 84(Reapproved 2002)An American National StandardStandard Practice forEstablishing Consistent Test Method Tolerances1This standard is issued under the fixed designation D 4356;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice should be used in the development of anytest method in which the determination value is calculated frommeasurement values by means of an equation.The practice isnot applicable to such determination values as those calculatedfrom counts of nonconformities,ratios of successes to failures,gradings,or ratings.1.2 The purpose of this practice is to provide guidance in thespecifying of realistic and consistent tolerances for makingmeasurements and for reporting the results of testing.1.3 This practice can be used as a guide for obtaining theminimum test result tolerance that should be specified with aparticular set of specified measurement tolerances,the maxi-mum permissible measurement tolerances which should bespecified to achieve a specified test result tolerance,and moreconsistent specified measurement tolerances.1.4 These measurement and test result tolerances are notstatistically determined tolerances that are obtained by usingthe test method but are the tolerances specified in the testmethod.1.5 In the process of selecting test method tolerances,thetask group developing or revising a test method must evaluatenot only the consistency of the selected tolerances but also thetechnical and economical feasibility of the measurement toler-ances and the suitability of the test result tolerance for thepurposes for which the test method will be used.This practiceprovides guidance only for establishing the consistency of thetest method tolerances.1.6 This practice is presented in the following sections:NumberScope1Referenced Documents2TERMINOLOGYDefinitions3Discussion of Terms4Expressing Test Method Tolerances5Tolerance Symbols6SUMMARY AND USESSummary of Practice7Uses and Significance8MATHEMATICAL RELATIONSHIPSPropagation Equations9Tolerance Terms10Determination Tolerances11Consistency Criteria12APPLICATION OF PRINCIPLESProcedure13Mass per Unit Area Example14ANNEXESGeneral Propagation EquationAnnex A1Specific Propagation EquationsAnnex A21.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 123 Terminology Relating to Textiles2D 2905 Practice for Statements on Number of Specimensfor Textiles2E 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications3E 456 Terminology Relating to Quality and Statistics33.Terminology3.1 Definitions:3.1.1 determination process,nthe act of carrying out theseries of operations specified in the test method whereby asingle value is obtained.(Syn.determination.See Section 4.)3.1.1.1 DiscussionA determination process may involveseveral measurements of the same type or different types,aswell as an equation by which the determination value iscalculated from the measurement values observed.3.1.2 determination tolerance,nas specified in a testmethod,the exactness with which a determination value is tobe calculated and recorded.3.1.2.1 DiscussionIn this practice,the determination tol-erance also serves as the bridge between the test resulttolerance and the measurement tolerances.The value of thedetermination tolerance calculated from the specified test resulttolerance is compared with the value calculated from thespecified measurement tolerances.1This practice is under the jurisdiction ofASTM Committee E11 on Quality andStatistics and is the direct responsibility of Subcommittee E11.20on Test MethodEvaluation and Quality Control.Current edition approved March 30,1984.Published August 1984.2Annual Book of ASTM Standards,Vol 07.01.3Annual Book of ASTM Standards,Vol 14.02.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.3.1.3 determination value,nthe numerical quantity calcu-lated by means of the test method equation from the measure-ment values obtained as directed in a test method.(Syn.determination.See Section 4.)3.1.4 measurement process,nthe act of quantifying aproperty or dimension.(Syn.measurement.See Section 4.)3.1.4.1 DiscussionOne test method determination mayinvolve several different kinds of measurement.3.1.5 measurement tolerance,nas specified in a testmethod,the exactness with which a measurement is to be madeand recorded.3.1.6 measurement tolerance propagation equation,nthemathematical formula,derived from the test m