Having Confidence in Specifications

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Having Confidence in Specifications (61 KB)

This paper presents some of the challenges in creating instrument specifications from a manufacturer’s perspective and some of the difficulties using specifications as an estimate of uncertainty from a user’s perspective. Despite the difficulties, specifications are the most common means of determining the Type B uncertainty for the standard when making a GUM (Guide to Uncertainty of Measurement) compliant uncertainty analysis. An explanation is presented for the practice of providing 95% and 99% confidence specifications, warranting only the 99% specifications, and verifying the 99% specifications to 95% confidence.