ASME B89.7.6:2019 pdf free download Guidelines for the Evaluation of Uncertainty of Test Values Associated With the Verification of Dimensional Measuring Instruments to Their Performance Specifications
1 scoPE
This Standard provides guidelines for evaluating the uncertainty of test values obtained when verifying dimensionalmeasuring instruments’ to an ASME B89 testing protocol. The scope is limited to the case in which the test measurandisthe error of indication at a rated operating condition; hence, test measurands such as the “worst possible” error ofindication that might occur at any operating condition (including those conditions that are not tested) are outsidethe scope of this standard.
ASMEB89testing protocols are composed of many individual tests, each test yielding one test value that is an estimateof the instrument’s measurement error at the particular operating condition tested, and this test value is comparedagainst the maximum permissible error(MPE)(specified for thatrated operating condition]using the protocol’sdecisionrule. Although the MPE is specified by the instrument manufacturer for all rated operating conditions, the test valueuncertainty is associated only with the test value obtained at the particular operating condition prevailing at the momentthe test value was obtained (unless a correction to the indication is performed that is allowed by the test protocol).Because each test investigates the error of indication at a particular rated operating condition, the test value uncer-tainty does not include the robustness or comprehensiveness ofthe testing protocol, i.e..it does notaddressthe number oftests or their distribution over different rated operating conditions. This issue is addressed by the standardizationcommittee creating the testing protocol; the committee balances the number of tests against the amount of timeand effort to complete the testing protocol.
The scope of this Standard excludes issues associated with the evaluation of the uncertainty of future measurementresults on workpieces and focuses solely on the test value uncertainties used to verify the instrument’s performancespecification.Typically , the test value uncertainty is much smaller than the associated MPE value of the verification test.
2 DEFINITIONS
The following definitions are specific to this Standard:
instrument: the measuring system that is under verification to its performance specification.NOTE: In this Standard, the term “instrument” is equivalent to “instrument under verification.”
verification system: the measuring system that is used to verify an instrument to its performance specification.NOTE: In this Standard, the verification system includes everything necessary to execute the testing protocol. This includes thecalibrated reference quantity, equipment used in the transfer process, the human operator (if one is involved), computationsand any other analysis needed, environmental and other conditions required by the instrument under verification, and anyinput quantities required to realize the measurand of the verification test.
3 REFERENCES
The following is a list of publications referenced in this Standard:ASME B89.1.13-2013,Micrometers
ASME B89.1.14-2018,Calipers
ASME B89.4.10360.2-2008,Acceptance ‘Test and Reverification Test for Coordinate Measuring Machines (CMMs)一Part 2: CMMs Used for Measuring Linear Dimensions (Technical Report)
ASME B89.7.1-2016, Guidelines for Addressing Measurement Uncertainty in the Development and Application ofASME B89 Documents
ASME B89.7.2-2014, Dimensional Measurement Planning
ASME B89.7.3.1-2001, Guidelines for Decision Rules: Considering Measurement Uncertainty in Determining Conformance to Specifications
ASME B89.7.3.2-2007, Guidelines for the Evaluation of Dimensional Measurement Uncertainty
ASME B89.7.3.3-2017, Guidelines for Assessing the Reliability of Dimensional Measurement Uncertainty Statements
ASME B89.7.4.1-2005, Measurement Uncertainty and Conformance Testing: Risk Analysis
ASME B89.7.5-2006, Metrological Traceability of Dimensional Measurement to the SI Unit of Length ASME Y14.5-2018, Dimensioning and Tolerancing
Publisher: The American Society of Mechanical Engineers (ASME), Two Park Avenue, New York, NY 10016-5990 (www.asme.org)
4 BASIc cONCEPTS OF TEST VALUES AND TEST VALUE UNCERTAINTY4.1 Introduction
ASME B89 standards describe the testing protocols used to specify the performance of dimensional measuring instru-ments.Verification of an instrument to its MPE is based on a decision rule (e.g, see ASME B89.7.3.1) that determineswhether a test value (obtained per the testing protocol) is within its MPE specification. Different test values may havedifferent test value uncertainties,e.g.,due to differenttesting temperatures ordifferent uncertainties ofcalibratedgaugesused in the verification.
ASME B89.7.6:2019 pdf free download
