standards, but until recently little calibration measurement data have been available for common test equipment. The advent of new calibration data systems such as MUDCATS? and others has produced a plethora of as-found and as-left measurement data ripe for analysis. Some of this data flatly rejects old assumptions of Gaussian measurement behavior for some types of common test equipment. ISO Standard 17025 has extended the requirement for reported measurement values and uncertainty statements from calibration standards to calibrations of test equipment. The common practice of either assuming normality or using a K factor of 2 standard deviations comes into question. What is the correct approach to create 95-percent measurement uncertainty bands for common test equipment? This paper examines currently available empirical evidence for the normality assumption of the measurement error distribution by equipment class. This paper further answers the question, "Do the rule-of-thumb measurement uncertainty rules for measurement standards apply for test equipment?"
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