BS EN ISO 14253-2:2011 产品几何量技术规范(GPS).工件与测量设备的测量检验.GPS测量中,测量设备校准中和产品检验中不确定度的评估指南
Geometrical product specifications (GPS). Inspection by measurement of workpieces and measuring equipment. Guidance for the estimation of uncertainty in GPS measurement, in calibration of measuring equipment and in product verification
This part of ISO 14253 gives guidance on the implementation of the concept of the “Guide to the estimation of
uncertainty in measurement” (in short GUM) to be applied in industry for the calibration of (measurement)
standards and measuring equipment in the field of GPS and the measurement of workpiece GPS
characteristics. The aim is to promote full information on how to achieve uncertainty statements and provide
the basis for international comparison of measurement results and their uncertainties (relationship between
purchaser and supplier).
This part of ISO 14253 is intended to support ISO 14253-1. Both parts are beneficial to all technical functions
in a company in the interpretation of GPS specifications [i.e. tolerances of workpiece characteristics and
values of maximum permissible errors (MPEs) for metrological characteristics of measuring equipment].
This part of ISO 14253 introduces the Procedure for Uncertainty MAnagement (PUMA), which is a practical,
iterative procedure based on the GUM for estimating uncertainty of measurement without changing the basic
concepts of the GUM. It is intended to be used generally for estimating uncertainty of measurement and giving
statements of uncertainty for:
- single measurement results;
- the comparison of two or more measurement results;
- the comparison of measurement results — from one or more workpieces or pieces of measurement
equipment — with given specifications [i.e. maximum permissible errors (MPEs) for a metrological
characteristic of a measurement instrument or measurement standard, and tolerance limits for a
workpiece characteristic, etc.], for proving conformance or non-conformance with the specification.
The iterative method is based basically on an upper bound strategy, i.e. overestimation of the uncertainty at all
levels, but the iterations control the amount of overestimation. Intentional overestimation — and not underestimation
— is necessary to prevent wrong decisions based on measurement results. The amount of
overestimation is controlled by economical evaluation of the situation.
The iterative method is a tool to maximize profit and minimize cost in the metrological activities of a company.
The iterative method/procedure is economically self-adjusting and is also a tool to change/reduce existing
uncertainty in measurement with the aim of reducing cost in metrology (manufacture). The iterative method
makes it possible to compromise between risk, effort and cost in uncertainty estimation and budgeting.