FIELD: measurement technology.
SUBSTANCE: transducers are mounted onto item which has fixed value of tightening torque with specified tolerance. Transducer is preliminary balanced with precision of +-0,5% nominal output signal and resistance temperature factors of all arms of bridge circuit are determined when taking balancing resistor into account and temperature factor of bridge circuit is calculated. Transducer is mounted in technological mounting face to keep preset tightening torque (tightening torque at mounting of transducer on item during exploitation) and nominal value of output signal (output signal deviation under influence of nominal value of parameter to be measured). Transducer is mounted into technological mounting face with minimal value of tightening torque and initial unbalance of transducer is determined. Then test is repeated at maximal tolerant value of tightening torque, tightening torque transducer additive sensitivity is calculated as well as axial force at thread part of the transducer for preset tightening torque and change in axial force at change in temperature within specified range. Equivalent change of resistance temperature of bridge circuit is calculated depending on tightening torque. Additive temperature error while taking influence of transducer temperature sensitivity by tightening torque into account is calculated by means of temperature-independent compensation resistor which is switched into specific point of bridge circuit in parallel to working resistance strain gauge. Value of temperature-independent resistor is determined for simultaneous compensation of additive temperature error of transducer's measurement circuit and additive temperature error from tightening torque by one temperature-independent resistor. Temperature-independent compensation resistor is placed into selected arm and bridge circuit is brought to balance without introducing changes into resistance temperature factor of balanced arm.
EFFECT: improved precision during process of adjustment.
1 dwg
Authors
Dates
2005-12-20—Published
2004-06-04—Filed