Extending the Production Tolerance of a Gauge and Determining its Trueness

Gauges are widely used means for alternative control in mass production and, in some cases, in small-scale production. Similar to all measuring devices, their use is accompanied by the well-known errors Type I (α) and Type II (β). A basic requirement when designing gauges is that the values of these errors are equal to those of other measuring devices. Considering the development and improvement of technological processes, at present there is a real possibility to improve some of the gauges’ characteristics. The most important metrological characteristic of the conical gauge is the so-called base distance. The standardized design requirements that are introduced to prevent scrap significantly reduce the production tolerance of the gauge. This not only causes some difficulties in the production of gauges, but also increases the likelihood of incorrectly rejecting conforming parts. The paper presents an opportunity to extend the production tolerance of conical gauges by applying a novel way of determining the nominal diameter of its no-go part, and by calculating theoretically the associated risk Type I (α).