Question

RTDs and thermistors are both temperature-measuring devices that convert the measured temperature into a resistance change. What are the main differences between these two types of devices in respect of the materials used in their constructions, their cost, and their operating characteristics?

Answer 1

Both RTDs and thermistor is temperature sensor device which changes value of resistance as temperature changes. But there are many differences between them such as, linearity, RTDs are very linear where as thermistor are less linear. Sensitivity, thermistors are very sensitive device which reflects Any negligible changes in temperature.

For RTDs pure metals are used such as copper, Nickel or platinum whereas for thermistor, pure metals are not used, in this metal oxide are used. Thermistor are negative temperature coefficient (NTC) for which semiconductor material, cobalt, nickel, iron, manganese, titaniums are used. In this as temperature increases Resistance value decreases. It also shows positive temperature coefficient (PTC) in which Resistor value increase as temperature increases.

As both RTDs and thermistor have different applications, it shows different characteristics RTDs used for wide range temperature measurement whereas thermistor are for home appliances hence it has narrow band temperature range. RTDs shows linearity, less accurate, slow and bulky whereas thermistor is non linear, highly accurate, fast and many more.

RTDs are Cheaper while thermistor is costlier due to high sensitive use.

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