Full range centigrade temperature sensor using LM35

The circuit based project describes the use of Temperature sensor LM35. This basic module finds lot of application in industries for measuring and controlling temperature.

This simple project has a circuit is based around the temperature sensor LM35, which senses the surrounding temperature and gives the corresponding voltage output at its output pin, its output voltage when multiplied by 100 gives the temperature sensed in degrees. By using this fact the reference can be set accordingly.

LM35 is a temperature sensor. Normally it can give readings from 2 degree centigrade to 150 degree centigrade but in this project, connecting a resistor to Vout through a negative voltage –Vs of value (Vs /50micro ampere) increases its range from -55 degree centigrade to +155 degree centigrade.

For every degree rise in temperature its output voltage increases by 10 mv, and this could be calibrated too.

LM 35 is highly preferred as it possesses low self heating and does not cause more than 0.1 oC temperature rise in still air.