Measuring accurate resistance of NTC thermistors

We sometimes get customer inquiries about how to measure the resistance of NTC thermistors, such as NCP18XH103F03RB from Murata. It can be a challenge to measure these devices’ resistance because NTC resistance are changed by ambient temperature. Slightly increasing or decreasing temperature will affect the change of resistance.

Here is an example of Murata NTC thermistors’ resistance characteristic in different temperatures.

Therefore it is important when measuring the resistance of NTC thermistors to control the ambient temperature precisely. Here are some notes that may help you in measurement.

  1. Do not touch the components and circuit boards during the measurement, because your body temperature will affect the measurement. Anyone’s breathing and air flow to the components are also restricted.
  2. NTC thermistors should be put nearby the measuring area. If the thermometer is far from the measuring area, the measuring area temperature might be different from thermometer temperature.
  3. Please refer the Resistance vs Temperature table and aware the specific value in your measuring temperature.
  4. As the measurement with high accuracy in air is very difficult, Murata recommends measuring the resistance value in a liquid bath for measuring in high accuracy.

To learn more about NTC resistance measurement in Labs, please check out this Murata Video.

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