LM35 TEMPERATURE SENSOR
The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required to subtract a large
constant voltage from its output to obtain convenient Centigrade scaling.
The high-accuracy version of the LM35 does not require any external calibration or trimming to provide typical accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C temperature range. (NOTE: The commercial versions of the LM35 like LM-35DZ typically sold have less accuracy. See the chart below).
Connect the LM35 to +5V and Gnd and the output to an Arduino Analog Input, Similar to this:
The full Datasheet is here: