what is thermister?

Learn to google.

It's spelt "thermistor" actually. It's a temperature dependent resistor.

Graham

Temperature dependent resistor. Resistance changes in a predictable way as temperature changes.

PTC thermistors = positive temperature coefficient= resistance rises in some way as temperature rises. Some vary very linearly with temperature (metallic), and some switch from low resistance to very high resistance over a small temperature range (semiconductor).

NTC thermistor = negative temperature coefficient= resistance falls in some way as temperature rises.

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Its a spray nozzle that cools you off with a misting spray when the temperature reaches a certain point. You smart guys thought he spelled it wrong.