Mechanical strain gauge for automatic data logging - has thermal compensation element, connected to resistive wire elastomeric system, having lower expansion coefficient than wires

摘要

The strain gauge can be adjusted and calibrated after being mounted on the component under test. A sensor (1) has two extensometers (3,4) and two compensating thermosensitive resistors (5,6). The sensor (1) is connected to an intermediate component (9) which is connected to a temp. compensating mechanical component (10). The intermediate component (9) has a linear coefficient of expansion smaller than the compensating component (10). On this compensating component (10) are placed a heating component (15) and a thermosensitive resistor (16) used to adjust the calibrating strain of this component (10). The electrical components (3,4,5,6) are mounted in two arms of a bridge, each containing an extensometer (3 or 4) in series with a thermosensitive resistor (5 or 6). One arm end is connected to the heating component (15) and the other to the thermosensitive resistor of the compensating component (10).