NTC resistors

(NTC: short for Negative Temperature Coefficient)

NTC resistors, sometimes also called thermistors, are temperature sensors with the property of conducting electrical currents better at higher temperatures. As soon as the temperature drops again, the resistance increases and thus less electrical current flows once more.   

As a rule, NTC resistors consist of semiconductor materials such as iron oxide. However, there are also different alloys that can have similar properties.

NTC resistors are specified with the ohm value at room temperature of 25 °C. Temperature detection is possible between -40 °C and +200 °C. The decrease and increase in resistance is not linear, but is read off in characteristic curves.

In addition to NTC resistors, PT100, FeCuNi or Ni120 temperature sensors are also used in hot-melt adhesive melters to implement electronic temperature control.