How to choose a temperature sensor?

Temperature is a very critical parameter that must be controlled in industrial production. It directly affects the quality of industrial products, equipment and personal safety. The choice of temperature detection instrument should not blindly require high measurement accuracy, wide range, and high degree of automation, but should combine various factors such as the specific process in industrial production, the actual situation of the measured medium, and the economy. The principle to be followed is that the upper and lower limits of the measured temperature of the testing instrument should be greater than the fluctuation range of the temperature of the measured medium, the measurement accuracy meets the technical requirements of the production process, the use mode meets the observation needs of the measurement personnel, and it is convenient for daily maintenance work. Choose the most economical and affordable testing instrument.

 

According to the range requirement

 

The temperature of the measured medium is a very critical basis for choosing a suitable measuring instrument. If you are measuring room temperature, you can choose thermocouple thermometers, resistance thermometers, pressure gauges, and bimetal thermometers.

 

1. The characteristic of the organic liquid glass thermometer is that its indicator liquid is red, which is convenient for reading, but it cannot charge the contacts. Therefore, when the temperature is lower than 100°C and the medium that does not need to send a signal is measured, the organic liquid glass thermometer can be preferred. The main advantages of bimetal thermometers are clear scale, vibration resistance, and no mercury, so when the temperature of the measured medium is lower than 300℃, it is best to choose a bimetal thermometer.

 

2. If the stability of the measured medium is lower than 150℃, you can choose copper thermal resistance; if the temperature of the measured medium is within the range of 300℃～600℃, you can choose a nickel-chromium copper thermocouple. 3. But because of the copper alloy wire Easy to oxidize, it is best to choose a nickel-chromium-copper thermocouple. The chromium-nickel-silicon thermocouple is used to measure the steam temperature above 500°C.

 

4. If the temperature of the measured medium is between 600°C and 1000°C, a nickel-chromium-nickel-silicon thermocouple can be selected

 

5. If the temperature of the measured medium is between 1000°C and 1300°C, platinum rhodium platinum thermocouples should be used.

 

6. If the temperature of the measured medium is very high, you can choose a radiation pyrometer or an infrared pyrometer.