High-precision temperature measuring device and method

Abstract

The invention provides a high-precision temperature measuring device and a high-precision temperature measuring method. The device comprises a low-drift voltage reference circuit part, an isolation circuit measuring part, a platinum resistor temperature sensor and a precision instrument amplifying circuit part, wherein the low-drift voltage reference circuit part consists of a high-precision voltage reference and a vernier slide rheostat and provides low-drift reference voltage for the isolation circuit measuring part; the isolation circuit measuring part consists of a high-precision amplifier and a precision resistor and is used for providing a constant flow source for the platinum resistor temperature sensor; the platinum resistor temperature sensor adopts a four-wire system connecting method, wherein two wires are connected to the isolation circuit measuring part to serve as power leads and the other two wires are connected to the precision instrument amplifying circuit part to serve as sensing leads; and the precision instrument amplifying circuit part consists of a precision instrument amplifier and a precision resistor and controls the gain of the precision instrument amplifier by changing the resistance of the precision resistor. The high-precision temperature measuring device and the high-precision temperature measuring method have the advantage of implementing high-precision four-wire system temperature measurement of the platinum resistor temperature sensor through the precision instrument amplifier, and are applied in the field of precision temperature measurement with the advantages of low cost, high precision and high stability and consistency.

Description

technical field [0001] The invention relates to a temperature measuring device, in particular to a high-precision temperature measuring device and a measuring method thereof which utilize platinum resistors for four-wire temperature measurement. Background technique [0002] The platinum resistance temperature sensor uses the physical characteristic that the resistance value of platinum metal will change with the temperature. It has good reproducibility and stability, and the temperature range is wide, which can reach -200~ 650°C, widely used in the field of industrial temperature measurement and aerospace precision temperature measurement, and is made into a standard thermometer for measurement and calibration. Therefore, the temperature measurement device of the platinum resistance temperature sensor is required to have high precision, high stability and multiple Road consistency and other characteristics. [0003] At present, most platinum resistance temperature measurin...

AI Technical Summary

Problems solved by technology

This method completely eliminates the error caused by the lead wire of the platinum resistor, but the disadvantage is that the cascade connection of three amplifiers makes the measurement accuracy difficult to control, increases the input voltage offset and input noise, and uses three precision operational amplifiers to increase the circuit Cost and circuit area, and multi-channel consistency is not good

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