ASME PTC 19.1-2018 pdf free
ASME PTC 19.1-2018 pdf free.Test Uncertainty Performance Test Codes.
ASME PTC 19.1 incorporates two internationally accepted methods of propagating uncertainties in measured parameters to a derived test result.
1-2.1.1 Taylor Series Method (TSM). This method of propagation is consistent with ISO/IEC Guide 98-3 (GUM) 121. The TSM requires the determination of sensitivity coefficients for each input variable (how the result is affected by variations In the input variables) and standard uncertainties for each error source.
1-2.1.2 The Monte Carlo Method (MCM). This method of propagation is consistent with JCGM 101 131. The MCM requires estimation of probability distributions and standard uncertainties (standard deviations) for each error source.
The distribution determined as the output of an MCM analysis allows direct determination of the lower and upper limits of a coverage interval that contains a specified percentage of the distribution. Thus there are no additional assumptions required to arrive at an expansion factor,” as is necessary in the TSM approach, to obtain a confidence interval estimate.
1-2.2 Uncertainty Propagation Classifications
This Standard uses two major classifications for errors and uncertainties: systematic and random. The ISO GUM uses a different classification for uncertainties: Type A and Type B.
1-2.2.1 Systematic. Systematic errors, whose effects are estimated with “systematic standard uncertainties,” do not cause scatter in test data.
1-2.2.2 Random. Random errors, whose effects are estimated with random standard uncertainties,” cause scatter in test data.
1-2.2.3 ISO GUM CLassification. The ISO GUM uses a different classification: Type A uncertainties are evaluated with statistical methods and Type B uncertainties are evaluated using other means, such as models or judgment. The terms identify the pedigree of the error sources.
The uncertainty of a test result is independent of whether the elemental uncertainties are classified as systematic or random, or as Type A or Type B. Regardless of the uncertainty classification used, the calculated uncertainty of the result will be the same. While this Standard utilizes systematic and random terms, there may be situations where it is useful to classify elemental uncer-
tainties by effect, source, or both.
1-3 APPLICATIONS This Standard is intended to serve as a reference to other supplements in the ASME PTC 19 Series and to ASME performance test codes and standards in general. In addition, it is applicable for all known measurement and test uncertainty analyses.
NOTE: The nominal values for the parameters and the uncertainty levels used throughout this Standard are for ilustrative purposes only and are not intended to be typical of standard tests.Values and uncertainty levels shall be evaluated for the specific test and measurement system used.ASME PTC 19.1 pdf download.
