Types of temperature sensors

Types of temperature sensors
1. Contact temperature sensor
The characteristics of the contact temperature sensor: The sensor is directly in contact with the object to be measured for temperature measurement. Due to the heat of the object to be measured, it is transferred to the sensor, which reduces the temperature of the object to be measured, especially when the heat capacity of the object is small, the measurement accuracy is low.In this way, to measure the true temperature of the object, the prerequisite is that the heat capacity of the object to be measured must be large enough.
2. Non-contact temperature sensor
The non-contact temperature sensor mainly uses the heat radiation of the measured object to emit infrared rays to measure the temperature of the object and can be used for remote measurement. The manufacturing cost is relatively high, but the measurement accuracy is relatively low. The advantages are: it does not absorb heat from the object to be measured; it does not interfere with the temperature field of the object to be measured; continuous measurement does not produce consumption; the response is fast, etc.
In addition, there are microwave temperature measurement temperature sensors, noise temperature measurement temperature sensors, temperature map temperature measurement temperature sensors, heat flow meters, jet thermometers, nuclear magnetic resonance thermometers, Mossbauer effect thermometers, Josephson effect measurement Thermometers, low-temperature superconducting conversion thermometers, optical fiber temperature sensors, etc.
(1) Contact temperature sensor
1). Commonly used thermal resistance
Range: -260～＋850℃;
Accuracy: 0.001°C. After improvement, it can work continuously for 2000h, the failure rate is less than 1%, and the service life is 10 years.
2). Thermal resistance of pipe and cable
The temperature measurement range is -20～+500℃, the highest upper limit is 1000℃, and the accuracy is 0.5 grade.
3). Ceramic thermal resistance
The measuring range is -200～+500℃, and the accuracy is 0.3 and 0.15.
4). Ultra-low temperature thermal resistance
Two kinds of carbon resistors can measure the temperature of -268.8～253℃-272.9～272.99℃ respectively.
5). Thermistor
It is suitable for use in high-sensitivity small temperature measurement occasions. The economy is good and the price is cheap.
(2) Non-contact temperature sensor
1). Radiation pyrometer
It is used to measure the high temperature above 1000℃. There are four types: optical pyrometer, colorimetric pyrometer, radiation pyrometer and photoelectric pyrometer.
2). Spectral pyrometer
Henan Minghai Optoelectronics Technology Co., Ltd. (www.hnminghai.cn) developed the YCI-I type automatic temperature universal spectrum pyrometer developed by the former Soviet Union. Its measuring range is 400～6000℃. It adopts an electronic automatic tracking system to ensure sufficient Accurate precision for automatic measurement.
3). Ultrasonic temperature sensor
It is characterized by fast response (about 10ms) and strong directionality. At present, there are products that can measure 5000℉ abroad.
4). Laser temperature sensor
Suitable for temperature measurement in remote and special environments. For example, NBS company uses the laser of the helium-neon laser source as the optical reflectometer to measure very high temperature with an accuracy of 1%.