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Where the resistance of the material falls with temperature, it is said to exhibit a negative temperature coefficient. An example of an NTC material is carbon.
The video clip shows how the resistance of an NTC resistor falls as the surrounding temperature increases. Here we are using a candle as a simple heat source. The meter reading moves towards the right hand end of the scale when the thermistor gets hot. Note that, on simple analogue multimeters, zero resistance coincides with full-scale deflection. In other words, if the pointer moves to the right the resistance is falling whereas if it moves to the left the resistance is increasing.
<^< Positive Temperature Coefficient | Course index | Thermistors >^>
