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This page compares Thermocouple vs RTD vs Thermistor and mentions difference between Thermocouple,RTD and Thermistor w.r.t. functions, advantages and. RTD vs. thermistor vs. semiconductor IC. December 29, By Janet Heath Table 1: Comparison of temperature sensing technologies. Adapted from A. Thermistors and RTDs or Resistance Temperature Detectors are two The main difference between the two is the type of material that they are.

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Notify me of followup comments via e-mail. The emf result depends on the difference between the two filerype and is used to determine the temperature. Thermocouple, coldjunction compensation analog approach. No current flows in the second pair, so lead resistance has no effect on accuracy.

Thermistor vs bdtween temperature measurement accuracy. Application notespractical temperature measurements cont. The most important factor to be considered when selecting a pair of materials is the thermoelectric difference between the. Two wires of fiiletype metals which are joined together to form Hot junction. Lead wire resistance should be considered, and adopting three and four wire connections can eliminate connection lead resistance effects from measurements.

Thermistors are made out of ceramic or polymer while RTDs are made out of pure metals. A typical thermistor shows a large negative temperature.


The major difference between the rtd and the thermistor is that the rtd is made of metal, whereas the semiconductor material is used for thermistor. Electrical temperature measurement is used in a wide variety of industries. The thermocouple is a component filetypee for thermocoouple of temperature. This means that when long distances are a must, one must employ transmitters when using RTDs.


RTDs are general used in industrial installation while thermistors are used in common home appliances. In NTC themistor resistance is inversely proportional to the temperature and hence resistance decreases when temperature increases.

Thermistors are a type of resistor with an electrical resistance that possesses either a negative or positive temperature coefficient of resistivity. Resistance Temperature Detectors RTDsalso referred to as platinum resistance thermometers PRTs or resistance thermometers, are temperature sensors that change resistance at a predetermined rate in response to variation in temperatures.

Compared to RTDs, thermistors can only be used within a smaller range of temperatures. Comparison of thermocouples, thermisyor, and thermistors.

Following are the advantages of thermocouple: They are very cost effective solution for wide range of temperature measurement with reasonable accuracy. Identifying different types of temperature detectors easa. The transfer function of an rtd is not perfectly linear.

Tigard, OR Following are differwnce disadvantages of thermocouple: They respond filetupe few hundred milliseconds. If one thermocouple is maintained at a temperature different from that of the other, an electrical voltage proportional to this temperature difference will be produced by the circuit. In PTC thermistor resistance is directly proportional to the temperature and hence resistance increases when temperature increases and viceversa. Electrical temperature measurement is used in a wide variety of industries.


This additional conductor will then also experience the temperature gradient, and develop a voltage of its own differnece will oppose the original; the magnitude of this effect depends upon the metal themristor use. Following are the disadvantages of RTD: Thermistors are commonly made with ceramic or polymer materials while RTDs are made of pure metals. The figure-2 depicts temperature vs voltage graphs for different thermocouple types viz.

This results into effect known as self heating.

Difference between Thermocouple,RTD and Thermistor

As shown in the figure, there are two junctions in the thermocouple “measurement or Hot junction” and “reference or Cold junction”.

The figure-1 depicts simple thermocouple construction.

Hence they are safe compare to all the other types viz. The values of the lead resistance can only be determined in a separate measurement without the resistance thermometer sensor and therefore a continuous correction during the temperature measurement is not possible.

Thermistors are able to detect sudden changes in temperature much quicker, allowing the connected devices to execute important decisions more promptly.

Thermocouple tc, resistance temperature detector rtd, thermistor, infrared detector, and via semiconductor or integrated circuit ic temperature sensors.

Comparison of Thermocouples, RTDs, and Thermistors Electrical temperature measurement is used in a wide variety of industries.