New concepts in specifications, operators and uncertainties and their impact on measurement and instrumentation

Abstract

“Geometrical product specifications (GPS)—General Concepts—Part 2: Basic tenets, specifications, operators and uncertainties” (ISO/TS 17450-2:2002) was recently published by ISO TC 213 “Dimensional and geometrical product specifications and verification”. This document defines a number of new concepts that provide the underpinnings for a new generation of standards for geometrical product specifications and have the potential of revolutionizing how we think about specification and verification. It enhances the specification language by defining specifications as ordered sets of operations, a much richer language than the simplistic notion of tolerance zones. Additionally, it expands the concept of uncertainty from being something measurement related to being the universal currency for quantifying ambiguity in requirements, specifications and verifications. These new concepts present new opportunities and new challenges both to metrologists and to providers of metrology instrumentation. This paper explores some of these opportunities and challenges.