What kinds of temperature sensors are there?

There are four kinds of temperature sensors, namely: thermocouple sensor, thermistor sensor, resistance temperature detector and IC temperature sensor.

1. Thermocouple sensor: directly measure the temperature, convert the temperature signal into a thermoelectromotive force signal, and convert it into the temperature of the measured medium through the electrical instrument. The basic principle of thermocouple temperature measurement is that two material conductors with different compositions form a closed loop. When there is a temperature gradient at both ends, there will be a current in the loop, and then an electromotive force will be generated between the two ends, which is the so-called Seebeck effect.

2. Thermistor sensor: The main component of thermistor sensor is thermistor. When there is thermal radiation around the thermistor material, it will absorb the radiant heat, which will lead to the increase of temperature and the change of material resistance.

3. Resistive temperature detector: Platinum, copper or nickel are usually used. They have large temperature coefficient, quick response to temperature change, resistance to thermal fatigue, and easy processing and manufacturing into precision coils.

4.IC temperature sensor: the integrated sensor is made of silicon semiconductor integrated technology, so it is also called silicon sensor or monolithic integrated temperature sensor. The main characteristics of analog integrated temperature sensor are single function, small temperature measurement error, low price, fast response, long transmission distance, small size and low power consumption. Suitable for long-distance temperature measurement and control, without nonlinear calibration and simple peripheral circuit.

Application of temperature sensor

Special temperature sensor must be used in biomedical applications. Its most important features are low power consumption, good long-term stability and high reliability, and its accuracy is less than 0. 1℃ between 32-44℃. Integrated temperature sensors have been reported in automation applications and microbial thermal detection applications, although their characteristics and requirements vary greatly according to each special application.

The current intelligent temperature sensor can meet the special application requirements of low cost, long-term stability and reliability, and powerful digital interface and communication system. Low-cost integrated temperature sensors and transmitters have appeared and have been applied to consumer products, such as washing machines, refrigerators, air conditioners and so on. Low cost, no need for external components and simple on-chip correction in the manufacturing process are special requirements for consumer products. In the range of 20- 100℃, the measurement accuracy should reach 0.5℃.