Softgauges for surface texture

Surface texture plays an important role in the specification of a precision workpiece. However, the route of traceability for surface texture measurements is not well developed. One of the main technical obstacles is the lack of tools to check traceability of the software of surface measuring instruments and to estimate uncertainty contributed by the software. To this end, the concept of softgauges (i.e. software measurement standards) for surface texture has been introduced into the international standards.

The presented thesis documents the realisation of softgauges for surface texture, which is a part of the National Measurement System in the UK. These standards, in the form of the reference dataset with reference results, have been developed by both simulation and experimental methods. The analysis of software uncertainty has been undertaken. These measurement standards have been used to verify both reference software(developed by the National Measurement Institutes) and commercial packages (developed by instrument manufacturers). In addition, the evaluation of the measurement uncertainty in workshop level has been carried on.

These developed standards provided a novel route to demonstrate metrological traceability of most surface profile parameters. Currently, these standards are distributed via the internet by the National Measurement Laboratory (NPL) in the UK. These standards are also recognised by NIST in the USA and PTB in Germany, and these organisations would also provide a suitable vehicle to distribute of the results of this study.