Thermocouple cold junction compensation bridge, thermocouple assembly and temperature sensor

Abstract

The invention provides a thermocouple cold junction compensation bridge. The thermocouple cold junction compensation bridge comprises a first rated resistor, a second rated resistor, a third rated resistor and a thermistor which are annularly connected end to end; a bridge circuit power supply which comprises a positive electrode and a negative electrode, wherein the positive electrode is electrically connected between the first rated resistor and the second rated resistor, and the negative electrode is electrically connected between the third rated resistor and the thermistor; and a cold endof a thermocouple electrically connected between the thermistor and the first rated resistor. Due to the fact that the thermistor is arranged in the compensation bridge, when the temperature of an environment where the cold end is located changes, the potential increment at the two ends of a bridge circuit correspondingly compensates for the reduction amount of thermoelectric potential of the thermocouple. The compensation bridge is simple in structure, used elements are simple and easy to obtain, and the problems of redundant arrangement of elements in a circuit, large occupied space and difficulty in integration in the prior art are solved. The invention also provides a thermocouple assembly with a thermocouple cold junction compensation bridge and a temperature sensor.

Description

technical field [0001] The invention relates to the technical field of temperature detection, in particular to a thermocouple cold junction compensation bridge, a thermocouple assembly and a temperature sensor. Background technique [0002] In the fields of industrial production, intelligent processing and wearable electronic devices, the demand for temperature detection is getting higher and higher. Thermocouple is a more commonly used temperature sensor in temperature measurement. Its main advantages are wide detection range and adaptability to various atmospheric environments. It is also strong, low in price, does not require power supply, and has low cost. [0003] However, the thermoelectric potential of a thermocouple is not only related to the temperature of the hot end, but also related to the temperature of the cold end. Only when the temperature of the cold end is constant, the thermoelectric potential can correctly reflect the temperature of the hot end. Due to t...

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Problems solved by technology

[0004] In the process of realizing the present application, the inventor found that there are at least the following problems in the prior art: the existing method of calculating and correcting the measurement deviation by substituting the formula and the method of placing the cold junction of the thermocouple in the ice-water mixture are inconvenient to use and complicated process

The compensation circuit set by the existing unbalanced bridge compensation method usually has redundant components in the circuit, resulting in a larger circuit footprint and the problem that it cannot be directly integrated into the thermocouple

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