Beschreibung
The sensory equipment of components of large production machines plays a major role for quality monitoring. In portal milling machines, conventional foilbased strain gauges can be applied manually on guide carriages in order to measure the process forces and torques in all directions. Here, an improvement regarding accuracy, positioning and automatability concerning the sensor application is aimed by directly deposited thin-film sensors. Therefore, this article shows and evaluates a method for trimming of sputtered resistive thin-film strain gauges during their vacuum plasma fabrication process. In this way, an adjustment of the output signal of a thin-film chromium Wheatstone full-bridge circuit to 0.02 mV/V is possible, assuring a proper functionality with low apparent strain values of 6 μm/m up to temperature values of 90 °C.
