ERASABLE-FOIL RESISTANCE COMPENSATION OF STRAIN GAGE TRANSDUCERS

摘要

ABSTRACT OF THE DISCLOSUREA strain-gage transducer incorporating a plurality ofelectrical-resistance strain gages coupled together in a bridgenetwork is caused to remain zero-balanced under varying-tempera-ture conditions by way of dual-resistance foil-type unit inter-posed at one of the output corners of the bridge with its twolike foil-resistance elements occupying adjacent arms. The foilmaterial is selected to exhibit a resistance change with tempera-ture representing a factor which enables a target room-tempera-ture measurement to be calculated once a rate of change of bridgeoutput with temperature has been determined from measurementstaken while the unstrained transducer is held at different temperatures. Relatively broad surfaces of the foil elements are leftexposed, and the unit of which they are a part is so disposed inrelation to the transducer structure that the exposed foil isaccessible for controlled erasure-type abrasion which will bringabout the target measurement and attendant compensation.