ASTM_D_3244_-_12.pdf

Designation:D324412An American National StandardStandard Practice forUtilization of Test Data to Determine Conformance withSpecifications1This standard is issued under the fixed designation D3244;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()indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe properties of commercial petroleum products are measured by standardized laboratory testmethods to check their conformance to specifications.Two or more measurements of the sameproperty of a specific sample by any given test method usually will not give precisely the same answer.Therefore,the test methods generally include a paragraph on the precision of results.This precisionis an expression of the reliability of the value of the measured property.Many difficulties that arise in interpreting specifications are due to test imprecision.Because of this,a true value of a property can never be determined exactly;and it is necessary to infer from measuredvalues the range within which the“true value”is likely to lie.The main purpose of this practice is toindicate how test imprecision should be interpreted relative to specification values.1.Scope*1.1 This practice covers guidelines and statistical method-ologies with which two parties,usually a supplier and areceiver,can compare and combine independently obtained testresults to obtain an Assigned Test Value(ATV)for the purposeof resolving a product quality dispute.1.2 This practice defines a technique for comparing an ATVwith a specification limit.1.3 This practice applies only to those test methods whichspecifically state that the repeatability and reproducibilityvalues conform to the definitions herein.1.4 The statistical principles and methodology outlined inthis practice can also be used to obtain an ATV for specificationconformance decision when multiple results are obtained forthe same batch of product within a single laboratory.For thisapplication,site precision(R)as defined in Practice D6299shall be used in lieu of test method published reproducibility(R).2.Referenced Documents2.1 ASTM Standards:2D1319 Test Method for Hydrocarbon Types in Liquid Petro-leum Products by Fluorescent Indicator AdsorptionD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6792 Practice for Quality System in Petroleum Productsand Lubricants Testing LaboratoriesD7372 Guide for Analysis and Interpretation of ProficiencyTest Program ResultsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of D02.94 onCoordinating Subcommittee on Quality Assurance and Statistics.Current edition approved Dec.1,2012.Published April 2013.Originallypublished as an appendix to the 1968 Annual Book of ASTM Standards,Part 18.Originally approved as a standard in 1974.Last previous edition approved in 2007as D324407a.DOI:10.1520/D3244-12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 2.2 ISO Standard:3ISO 4259 Determination and Application of Precision Datain Relation to Methods of Test3.Terminology3.1 Definitions:3.1.1 acceptance limit(AL),na numerical value thatdefines the point between acceptable and unacceptable quality.3.1.1.1 DiscussionThe AL is not necessarily the specifi-cation limit.It is a value that takes into account the specifica-tion value,the test method precision,and the confidence leveldesired for defining minimum acceptable quality relative to thespecification value.3.1.2 assigned test value(ATV),nthe average of all resultsobtained in the several laboratories which are consideredacceptable based on the reproducibility of the test method.3.1.3 determination,nthe process of carrying out theseries of operations specified in the test method whereby asingle value is obtained.3.1.4 dispute,nwhen there is a question as to productquality conformance to specification because a test valueobtained falls outside the specification limit(s).3.1.5 operator,na person who normally and regularlycarries out a particular test.3