FIELD: measuring techniques.
SUBSTANCE: invention relates to measurements. Proposed method consists in the following. First, heat-dependant resistor Rβm is mounted. The bridge measuring circuit is re-equalised within ±0.5% of the rated output signal without varying temperature coefficient of resistance (TCR) of the branch being equalised, for example, by laser or electro-erosion adjustment of strain gage mounted in adjacent arm of the bridge circuit relative to Rβm location branch. Initial output signals from equalised pickup Uoβ and Uoβt are defined at normal temperature To and operating temperature, respectively. Rating of compensation temperature-dependant strain gage Rβ is calculated from the formula
where Ri is the rating of the branch resistor whereto temperature-dependant compensation resistor is connected. Obtained compensation resistor rating is entered into measuring circuit via partial use of temporary compensation temperature-dependant resistor with subsequent final equalisation without varying TCR by laser or electro-erosion adjustment of strain gage mounted in opposite arm of the bridge circuit.
EFFECT: easier and more accurate adjustment.
Authors
Dates
2009-08-10—Published
2008-04-29—Filed