NTC and PTC Thermistors

There are two separate types of thermistors available on the market today: NTC and PTC. PTC stands for positive temperature coefficient and NTC is negative temperature coefficient. An NTC's resistance will decrease with temperature; where as, the resistance from PTCs will increase. Regardless of which thermistor is being used, it is important that the devices be tested prior using. This is the only way to ensure that temperature is being read accurately. Similar testing can be done for both NTC and PTC.

You can test the devices by keeping analogue multimeters in resistance mode. Once in resistance mode, you will want to connect the multimeter terminals onto the thermistor lead. The next step is adding heat. You can add heat to a thermistor by moving a heated soldering iron up to the tip. This will allow an individual to see whether they are using NTC or PTC thermistors, as well as telling whether the device is healthy or not.

If the change in temperature is not smooth, you might not have a properly functioning thermistor. If the readout on the meter is zero, you might also have a faulty thermistor.

This is only a rough test, and further tests can be done to give more accurate details.

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