Answer Will, It's just as it is labelled, it senses the temperature of the component or the room air, depending on what area of the fridge it is located. At room temperature it should have a resistance of 1,000 to 1,100 ohms and produce a voltage of .5 volts back to the control at 0 dgrs it has a resistance of 13,300 and a voltage of 2.8 volts and at 38 dgrs. has 3,200 ohms and a voltage of 1.2 volts. Based on the resistance and voltage, the control determines what the refrigerator needs to do as far as cooling, defrosting, and also assists in programming the defrost cycle time and pattern. Thanks and Good Luck Read More... Answered by AppliancePartsPros.com | Saturday, February 18, 2012