We’ve already shown that the thermistors are similar to the changing resistances ,it changes with changing according the temperature .so as to measure the temperature in our project using Arduino we use the voltage divider theory first to get the value of the resistance. Since the arduino will measure the voltage between the thermistor and a known resistance ,so we can easily find the value of the resistance. At last , the Steinhart-Hart equation is used to convert the resistance of the thermistor to a temperature reading. The Steinhart and Hart Equation is an empirical expression that has been determined to be the best mathematical expression for resistance temperature relationship of NTC thermistors.