Challenge for the Traceable Dimensional Measurement Using CMM in Factory Floor

Abstract

Dimensional measurement is a key process in the quality assurance of manufacturing. Not only classical one-dimensional measurement devices, several kind of three-dimensional coordinate measuring systems (CMSs) including coordinate measuring machines (CMMs) are used for dimensional measurement tasks in measurement rooms or in factory floors. For the purpose of the quality guarantee, the measurement for the validation on the products should be performed with the traceable manner. In the case of the dimensional measurement, the measurement results of the products should be stated as the corresponding values in the reference temperature, 20 °C. Therefore, at least the traceability of the length indication instruments and temperature-measuring equipment installed into the measuring device to be used should be ensured. Usually, the traceability of the instrument or equipment is ensured through the calibration on it. Now, typical CMMs in factory floor have non-calibrated temperature-measuring equipment because the equipment is hard to be detached off for the calibration, and therefore, the temperature-measuring equipment is usually left uncalibrated. Recently, a new procedure by which both the length indication instruments and temperature-measuring equipment installed into a CMM are able to be calibrated simultaneously is established. In this research, the traceable dimensional measurement using a CMM equipped with uncalibrated temperature-measuring instrument is developed by as an application of the established calibration procedure. Through the experiment, the traceable dimensional measurement using the CMM placed on the factory floor is demonstrated.