STRAIN-MEASURING DEVICE Russian patent published in 1995 - IPC

FIELD: measurement technology. SUBSTANCE: tested and standard resistance strain gages form external half-bridge of four-arm measuring bridge of strain-measuring device operating on d.c. current. There are also second d. c. power supply in the form of bank of capacitors, electronic switch, and control unit forming ripple-current source which performs simultaneous impulse heating of both resistance strain gages upon command coming from START pulse generator. If tested resistance strain gage is poorly stuck to surface, its test heating by end of test pulse will be higher than test overheat of standard resistance strain gage. Test unbalance of measuring bridge caused by this occurrence is detected by amplitude selector together with test current sensor, amplitude selector blocking unit, and logic unit, and is displayed on optoelectric indicator as adequate or inadequate quality of sticking. EFFECT: improved design. 1 dwg