Miniature force transducers with strain gauges

Abstract Miniature force transducers (MFTs) with strain gauges manufactured with diameters ranging from a few to 20 mm and heights from about 1 mm to 20 mm are used on the most varied technical fields. It is the essential problem of the measuring technique with MFTs that the strain gauges retroact on the measuring spring considerably and by this increase the measuring error at low thickness of the measuring spring. These measuring errors were investigated by experiment and by calculation on measuring springs and MFTs. They are: the zero shift depending on temperature, relative humidity and the MFT's geometry, the creep, the infuence of external and internal pressure and the infuence of the supply voltage. The MFTs' charac teristic frequencies and their sensitivity to accelaration are discussed. Various shaping and jointing techniques and some methods for the compensation of the effects discussed above are demonstrated. The strain gauges strongly influence the measuring errors at a thickness