Traceability of dynamic force and torque calibrations by means of laser Doppler interferometry

Abstract

In contrast to the fact that a huge class of industrial force and torque measurement applications are of dynamic type, the standard calibration methods for the facilitated transducers are still of static type. The presented paper gives an introduction to recent developments at the Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, towards new dynamic calibration methods for force and torque. In addition to the already established sinusoidal force calibration, two new facilities have been developed over the last three years which are concerned with the generation of impact forces and periodic torque respectively. For the primary dynamic force and torque calibration facilities the preferred way to provide traceability is the measurement of the motion of an accelerated mass or mass distribution. The means of measurement for primary calibration therefore are laser-Doppler-interferometers (LDI), which are utilized in very special ways.