Method and device for compensation of changes caused by temperature fluctuations of the zero position of the output signal of an expansion measurement transducer

摘要

A strain-gage transducer incorporating a plurality of electrical- resistance strain gages coupled together in a bridge network is caused to remain zero-balanced under varying-temperature conditions by way of dual- resistance foil-type unit interposed at one of the output corners of the bridge with its two like foil-resistance elements occupying adjacent arms. The foil material is selected to exhibit a resistance change with temperature representing a factor which enables a target room-temperature measurement to be calculated once a rate of change of bridge output with temperature has been determined from measurements taken while the unstrained transducer is held at different temperatures. Relatively broad surfaces of the foil elements are left exposed, and the unit of which they are a part is so disposed in relation to the transducer structure that the exposed foil is accessible for controlled erasure-type abrasion which will bring about the target measurement and attendant compensation.