ASME B89.7.6 pdf free download

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.
ASME B89.7.6 provides guidelines for evaluating the uncertainty of test values obtained when verifying dimensional measuring instruments’ to an ASME 1389 testing protocol. The scope is limited to the case in which the test measurand is the error of indication at a rated operating condition; hence, test measurands such as the worst possible error of indication that might occur at any operating condition (including those conditions that are not tested) are outside the scope of this Standard.
ASME 889 testing protocols are composed of many individual tests, each test yielding one test value that is an estimate of the instrument’s measurement error at the particular operating condition tested, and this test value is compared against the maximum permissible error (M PE) (specified for that rated operating condition) using the protocol’s decision rule. Although the MPE is specified by the instrument manufacturer for all rated operating conditions, the test value uncertainty is associated only with the test value obtained at the particular operating condition prevailing at the moment the 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 uncertainty does not include the robustness orcomprehensiveness of the testing protocol. i.e., it does not address the number of tests or their distribution over different rated operating conditions. This issue is addressed by the standardization committee creating the testing protocol; the committee balances the number of tests against the amount of time and effort to complete the testing protocol.
The scope of this Standard excludes issues associated with the evaluation of the uncertainty of future measurement results on workpieces and focuses solely on the test value uncertainties used to verify the instrument’s performance specification. 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 instrumenr Is equivalent to instrument under verlflcatlon
verification system: the measuring system that is used to verify an instrument to its performance specification.
NOTE: In this Standard, the verilication system includes everything necessary to execute the testing protocol. This includes the calibrated relerence quantity, equipment used in the transfer process, the human operator (if one is involved), computations and any other analysis needed, environmental and other conditions required by the instrument under verification, and any input 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 889.4.10360.2-2008, Acceptance Test and Reverification Test for Coordinate Measuring Machines (CMMs) — Part 2: CMMs Used for Measuring Linear Dimensions (Technical Report).ASME B89.7.6 pdf download.