LM335 - Precision Temperature Sensor
The LM135, LM235, LM335 are precision temperature sensors which can be easily calibrated. They operate as a 2-terminal Zener and the breakdown voltage is directly proportional to the absolute temperature at 10mV/°K.
Above data from STMicro - Circuit shows a design using LM335 for Temperature Control.
LM335 Cold Junction Compensation
Temperature Sensors like Thermocouples need cold junction compensation as a part of front end signal conditioning, this is done at the terminal block where the Thermocouple wires are terminated. This design has to be more accurate and broad, if the design we make has to work well in both Tropical and Temperate Climate Zones.
Thermocouple Temperature using DPM or DMM
Temperature measurement and control uses the Thermocouple and the Seebeck Effect for measurement. The most common is J Type as it is affordable. K is better and works well even at higher temperatures too.