Pt100 - Temperatur Sensors

-Thermowells for Pt100 resistance thermometers-

About the site

This is a private information page about electrical temperature measurement with resistance thermometers (e.g. Pt100, Pt500, Pt1000). My experiences of many years in the field of measurement and control technology are recorded. I do not take over any liability for incorrect information and would be pleased about further suggestions and requests for additions.
Please also visit my information page about variable area flowmeters: https://schwebekörper.de/en

Suppliers of Pt100

Links to selected manufacturers and suppliers of Temperature Sensors.

Tools

Thermowells for Pt100 resistance thermometers and thermocouples

Thermowells are hollow bodies that serve as a protective device for thermometers or other temperature measuring devices.
They are inserted directly into the medium and separate the thermometer mechanically and thermally from the medium to be measured.
This means that the thermometer itself does not come into direct contact with the liquid, gas or other substances, which both extends the service life of the device and protects the environment and operating personnel.
If the thermowell is installed and designed correctly, the temperature inside the thermowell is the same as in the process. Depending on the design, temperature changes result in a time-delayed temperature adjustment between the medium and the temperature sensor.
Thermowells allow the resistance thermometer to be replaced during operation and thus enable uninterrupted maintenance or replacement of the sensor.
They are usually installed under critical operating conditions, such as aggressive media, high pressures or high flow velocities.

Types of thermowells

Connection of thermowells

Material of thermowells

Thermowells are mainly made of stainless steel or, in the case of mechanical thermometers, brass.
If there are special operating conditions, special alloys such as Hastelloy®, Inconel® or Monel® are used.
Partial or full linings made of plastic (e.g. PTFE) are also used for high chemical stresses.
Very high temperatures or certain aggressive gases require the use of ceramic thermowells.
When selecting the thermowell material, the chemical resistance to the medium and the maximum permissible temperature and pressure resistance of the material must always be taken into account.