Thermometers base their physical functioning on the use of some physical quantity that varies with the temperature that typically can be the thermal expansion of a liquid, gaseous or solid substance.

The range of includes:

- Bimetallic thermometers (they have a bimetallic spiral inside the probe as a temperature sensor)
- Liquid expansion thermometers (usually used in places that are difficult to access and to overcome great distances.
- Gas expansion thermometers (they have advantages of less danger thanks to the inert gas filling usually nitrogen, argon etc ..)

They are supplied with alarm contacts, process connections, diameters and bulb length depending on the customer's needs.
They are suitable for hostile environments, have good accuracy and a low cost.