1K NTC Thermistor
This Negative Temperature Coefficient (NTC) Thermistor varies in resistance according to temperature. It is a simple way to measure air temperature or the temperature of an adjacent device or surface. The resistance is 1K Ohm at 30°C and decreases as temperature increases. It is extremely easy to interface to the analog input pins on an Arduino, Netduino or other microcontroller (PIC, AVR, etc.), as well as an easy device to use in analog circuits.

Dimensions: 5.6mm x 3.5mm, with 27mm long leads.

This is a must-have part for any hobbyist or young electronics enthusiast. Its great for classroom electronics demonstrations and science fairs. This is the sensor at the heart of electric fans, microwave ovens, air conditioners, etc.