Temperature sensor IC LM34/35, are used in various applications to detect temperature variations. These devices can switch off / on circuits when the temperature varies from the normal set level. LM 34 and LM 35 Integrated Circuits are precision temperature sensors widely used in temperature sensing applications. LM 34 senses temperature in Fahrenheit range while LM 35 senses temperature in Celsius (Centigrade) range. The output voltage of these sensors is linearly proportional to the temperature. LM 34 and LM35 sensors are too sensitive and the static electricity while handling may damage the device. You can make a Room Thermometer using Multi meter. If you use a Digital display unit, you can make a permanent set up.