Temperature Measurement

Comparison of Temperature Sensors – Industrial Process Control

The temperature sensors come in various types, each with its own set of characteristics suitable for specific applications.

Comparison of Temperature Sensors

Here we compared the popular temperature sensors in the below table. let’s have a look at it.

Parameter	Thermocouple	RTD (Resistance Temperature Detector)	Thermistor	Infrared	Bimetallic Strip	Semiconductor (IC)	Fiber Optic
Principle of Operation	Seebeck effect	Resistance varies with temperature	Resistance varies exponentially with temperature	Emission of infrared radiation	Mechanical bending due to thermal expansion	Bandgap of semiconductor varies with temperature	Light wavelength changes with temperature
Temperature Range	Wide (-200 to 2300°C)	Moderate (-200 to 850°C)	Limited (-100 to 300°C)	Wide (-50 to 1000°C)	Limited (-30 to 120°C)	Moderate (-55 to 150°C)	Wide (-200 to 800°C)
Accuracy	Moderate	High	Moderate to High	Moderate	Low to Moderate	Moderate to High	High
Response Time	Fast	Moderate	Fast	Fast	Slow	Fast	Fast
Sensitivity	Low	Moderate	High	Moderate	Low	Moderate	High
Cost	Low	High	Low	Moderate to High	Low	Moderate	High
Linearity	Non-linear	Linear	Non-linear	Non-linear	Non-linear	Linear	Linear
Self-heating	Low	Moderate	High	None	None	Moderate	None
Ease of Installation	Easy	Moderate	Easy	Moderate	Easy	Moderate	Moderate
Safety Aspects	Generally Safe	Generally Safe	Generally Safe	Limited (eye safety)	Generally Safe	Generally Safe	Generally Safe

Here’s a brief explanation of the terms used:

Principle of Operation: The basic principle that allows the sensor to measure temperature.
Temperature Range: The range of temperatures the sensor can accurately measure.
Accuracy: How precisely the sensor can measure temperature.
Response Time: How quickly the sensor can respond to changes in temperature.
Sensitivity: How much the output changes for a given change in temperature.
Cost: The relative financial outlay required to purchase and install the sensor.
Linearity: Whether or not the output is directly proportional to the temperature.
Self-heating: Whether the sensor itself generates heat during operation, which could affect its accuracy.
Ease of Installation: How simple it is to install the sensor.
Safety Aspects: Considerations regarding the use of the sensor in hazardous conditions.

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