TEMPERATURE MEASUREMENT METHOD Russian patent published in 2023 - IPC G01K7/16 

FIELD: temperature measurement.

SUBSTANCE: temperature measurement method consists in feeding a resistance thermometer connected by a two-wire line, shunted by a capacitor directly on its connecting contacts, through a series-connected reference resistor with rectangular voltage pulses with a duty cycle at which the average current through the resistance thermometer does not exceed the allowable value. At the end of the action of a rectangular pulse in the steady state, the voltage drop across the reference resistor and the voltage at the input of the two-wire line are measured, and after the circuit is broken, the voltage at the input of the two-wire line is measured with a given sampling step and the sum of voltage readings is accumulated until the end of the transient discharge of the capacitor on a resistance thermometer with saving the accumulated amount over a time interval t₁>1 and for the total time of the transition process. The resistance value of the resistance thermometer is determined by the value of the resistance of the reference resistor, the voltage drop across the reference resistor, the values of the two accumulated sums of readings and the value of the time interval t₁, and the measured temperature is determined from the calibration characteristic of the resistance thermometer.

EFFECT: reduced temperature measurement error caused by resistance of the wires with a two-wire connection of the resistance thermometer and a change in the time constant of the discharge of the capacitor shunting the resistance thermometer, interference in the measuring circuit, quantization noise.

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