Temperature measurement system and method

Abstract

The invention discloses a temperature measurement system and method. The system comprises a thermocouple sampling module, a thermal resistance sampling module, a measurement device and a temperature sensor. The thermocouple sampling module is used for collecting a thermocouple voltage signal of detected equipment. The thermal resistance sampling module is used for collecting a thermal resistance voltage signal of a cold end of the thermocouple sampling module. The temperature sensor is used for collecting the internal cold end temperature signal of the measurement device. The measurement device is used for selecting a cold end temperature compensation mode, and calculates the temperature of the detected equipment in the selected cold end temperature compensation mode. The invention also provides a temperature measurement method. The remote sampling employs the external compensation for guaranteeing the sampling precision. The short-distance sampling employs the internal compensation, thereby releasing one more sampling channel.

Description

Technical field [0001] The invention relates to the technical field of temperature measurement, in particular to a temperature measurement system and method. Background technique [0002] In the field of industrial control, many electrical control equipment need to detect temperature signals in order to realize the functions of monitoring, protection and control adjustment of the equipment. At present, the most widely used temperature detection element is a thermocouple. A thermocouple is a temperature sensor made of the junction of two different metal conductors. It is a device that converts temperature into voltage and can be used to measure physical quantities such as temperature. The measurable temperature range is large. As a sensor with high accuracy, simple structure, wide temperature measurement range, and small inertia, thermocouples are widely used. [0003] A thermocouple includes a hot end and a cold end. The hot end is also called the measurement end, which is the en...

AI Technical Summary

Problems solved by technology

However, when the device under test is far away from the measuring device, the actual cold junction temperature T1 of the thermocouple (the end of the thermocouple connected to the measuring device through a lead wire) and the cold junction temperature T2 of the measuring device (that is, the thermoelectricity of the signal processing circuit of the measuring device) Even signal input terminal) is different

At this time, if calculated according to T2, it will lead to the problem of inaccurate temperature measurement.

In addition, if the temperature sensor is set on the input terminal of the thermocouple signal, a temperature measurement channel needs to be occupied; if the temperature sensor is placed on the PCB board inside the measuring device, the temperature rise on the board will affect the accuracy of the cold junction temperature. Sex, also lead to inaccurate temperature measurement

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