ASME_B89.7.4.1-2005.pdf

AN ASME TECHNICAL REPO RTMeasurement Uncertainty and Conformance Testing:Risk AnalysisASME B89.7.4.1-2005(Technical Report)Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-ASME B89.7.4.1-2005(Technical Report)MeasurementUncertainty andConformance Testing:Risk AnalysisAN ASME TECHNICAL REPORTThree Park Avenue New York,NY 10016Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-Date of Issuance:February 3,2006This Technical Report will be revised when the Society approves the issuance of a new edition.Therewill be no addenda issued to this edition.ASME is the registered trademark of The American Society of Mechanical Engineers.ASME does not“approve,”“rate,”or“endorse”any item,construction,proprietary device,or activity.ASME does not take any position with respect to the validity of any patent rights asserted in connection with anyitems mentioned in this document,and does not undertake to insure anyone utilizing a standard against liability forinfringement of any applicable letters patent,nor assumes any such liability.Users of a code or standard are expresslyadvised that determination of the validity of any such patent rights,and the risk of infringement of such rights,isentirely their own responsibility.Participation by federal agency representative(s)or person(s)affiliated with industry is not to be interpreted asgovernment or industry endorsement of this code or standard.No part of this document may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue,New York,NY 10016-5990Copyright 2006 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.Copyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-CONTENTSForeword.ivCommittee Roster.v1Scope.12Definitions and Terminology.13Inspection Measurements and Pass/Fail Decisions.24Frequency Distributions:Variable Production Processes and NoisyMeasurements.35Probability Densities:Prior Information and Standard Uncertainty.66Workpiece Inspection:Measurements and Measurement Uncertainty.87Gauging(or Test)Limits and Guard Bands.108Controlling the Quality of Individual Workpieces.129Controlling the Average Quality of Workpieces.15References.18Figures1Tolerance Zone.32Frequency Distribution of a Sample of Spacers.33Fraction of Workpieces Conforming Versus Process Capability Index.54Process Probability Density for the Length of a Randomly Chosen Workpiece.75Probability Density for the Lengths of a Measured Workpiece.96Measurement Capability Index Versus Scaled Measurement Result.117Stringent Acceptance Zone.128Relaxed Acceptance Zone.129Desired Level of Confidence Defines an Acceptance Zone.1310Guard Band Chosen to Reduce the Probability of Accepting a Workpiece That IsToo Long.1411Stringent Acceptance Zone for Symmetric Two-Sided Guard Banding.1412Contingency Table for an Inspection Measurement.1613Contingency Table for the Worked Example.1714Producers and Consumers Risks for the Worked Example.1915Producers Risk Versus Consumers Risk for the Worked Example WithCpp 0.55 and Cmp 2.5.2016Producers Risk Versus Consumers Risk for Cpp 1.5.2117Producers Risk Versus Consumers Risk for Cpp 1.2218Producers Risk Versus Consumers Risk for Cpp23.2319Producers Risk Versus Consumers Risk for Cpp13.24Tables1Fraction Conforming Versus Process Capability Index.62Conformance Probability Versus Guard Band Multiplier.14Mandatory AppendicesIProperties of Gaussian Probability Densities.25IIRisk Calculations.27iiiCopyright ASME International Provided by IHS under license with ASME Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-FOREWORDThe ISO Guide to the Expression of Uncertainty in Measurement(GUM)is now the internation-ally accepted method of expressing measurement uncertainty 1.The U.S.has adopted the GUMas a national standard 2.The evaluation of measurement uncertainty has been applied forsome time at national measurement institutes;more recently,increasingly stringent laboratoryaccreditation requirements have increased the use of measurement uncertainty analysis in indus-trial calibration laboratories.In some cases,measurement uncertainty calculations have even beenapplied to factory floor measurements.Given the potential impact to business practices,national and international standards commit-tees are working to publish new standards and technical reports that will facilitate the integrationof the GUM approach and the consideration of measurement uncertainty in product conformancedecisions.In support of this effort,the ASME B89 Committee for Dimensional Metrology hasformed Subcommittee 7 Measurement