Common Temperature Sensing Technologies


#1

Temperature sensing is one of the more common technologies in today’s product applications.
To make a reliable temperature measurement, it is important to carefully select the right temperature sensor for the application. Understanding the advantages and disadvantages of the different types of temperature sensors will help to make the proper selections before a measurement.

Thermocouples, Thermistors (NTC / PTC), Resistance Temperature Detectors (RTDs) and Temperature sensing ICs are the most common temperature sensors used in the measurement.

Thermocouple Thermistor RTD Temperature Sensing IC
Typical Temperature Range (around) -270 to 1800°C 0 to 100°C -250 to 900°C -55 to 150°C
Linearity Poor Worst Good Best
Accuracy Good Calibration dependent Best Good
Advantages *Self-powered, rugged Fast response to temperature changes, high sensitivity *Most accuarate, most stable *Most Linear, digital interface
Disadvantages *Non-linear, reference required, least stable, least sensitive *Non-linear, limited temperature range, current source required *Current source required, small resistance change, slow *Power supply required, self-heating, limited temperature range
Typical Applications Extreme temperature sensing - oven, test equipment Low precision, moderate temperature range - hair dryer, protection circuits High precision, extended temperature - gas and fluid flow Computers, wearable devices, data logging