Working principle of temperature sensor

What is the working principle of a temperature sensor?

The working principle of a temperature sensor is mainly based on the principle of thermocouple, thermal resistor, and thermistor.

1. Thermocouple sensor

This sensor uses the thermoelectric potential generated by two different metals when the temperature changes to measure temperature. For example, the thermoelectric potential generated by a K-type thermocouple at 500°C is about 20 mV.

2. ‌Thermal resistor sensor‌

It includes the property that the resistance value of metal or semiconductor changes with temperature. For example, the resistance value of the PT100 thermal resistor is 100Ω at 0℃, and the resistance value increases by about 0.385Ω for every 1℃ increase in temperature.

3. ‌Thermistor Sensor‌

Its resistance value is extremely sensitive to temperature changes and is usually divided into two types: positive temperature coefficient and negative temperature coefficient. The resistance value of a negative temperature coefficient thermistor drops rapidly when the temperature rises.

4. Infrared temperature sensor‌

It measures temperature by receiving infrared radiation energy emitted by an object without contacting the object being measured.

5. DS18B20 Temperature Sensor‌

This digital temperature sensor uses the 1-Wire bus protocol to measure the ambient temperature through thermistor characteristics and converts the analog signal into a digital signal output. It can operate in the range of -55℃ to +125℃, and the measurement accuracy can reach ±0.5℃ in the range of -10℃ to +85℃.

Types of temperature sensor

GAIMC temperature sensors mainly involve ntc temperature sensor, ds18b20 temperature sensor, pt100/pt1000 temperature sensor, and the temperature humidity sensor.

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