FIELD: measurement equipment.
SUBSTANCE: invention relates to measurement equipment. The method consists in the fact that in case of load resistance Rl>500 kOhm they determine temperature coefficient of sensitivity (TCS) of the bridge circuit
and
at the temperature t+, and t-, corresponding to the upper and lower limit of the working range of temperatures, and non-linearity of the TCS of the bridge circuit
If the produced value Δαdo is positive, then the positive non-linearity of bridge circuit TCS is converted into the negative one by connection of a thermally dependent resistor Rainlet into the supply diagonal with simultaneous shunting of the inlet resistance of the bridge circuit with a thermally independent resistor Rsh. For this purpose they determine inlet resistance and TCS of inlet resistance, and also the TCS of strain gauges
and
under temperature t+ and t-, and they calculate non-linearity of TCS of the bridge circuit
is calculated. If
and Δαd are in the area of conversion of positive non-linearity of bridge circuit TCS into the negative one, then the rating of the thermally independent resistor Rsh is accepted as equal to the inlet resistance, the rating of the resistor is Rainletcalculated. Resistors Rainlet and Rsh are connected into the bridge circuit supply diagonal. The TCS of the bridge circuit is defined at the temperature t+ and t-, non-linearity of the bridge circuit TCS is calculated as Δαdo. If Δαdo takes the negative value, then compensation of multiplicative temperature error is carried out with account of the negative non-linearity of bridge circuit TCS by connection of the thermally independent Raoutlet, shunted by the thermally independent resistor Rdoutlet, into the outlet diagonal of the bridge circuit under resistance of load Rl≤1 kOhm.
EFFECT: higher accuracy of compensation.
3 tbl, 3 dwg
