- ifm temperature sensors
- Thermowells for temperature sensors
Thermowells for temperature sensors
High pressures, fast flow speeds and aggressive or abrasive media place special demands on temperature measurement in process environments. Thermowells reliably protect temperature sensors against mechanical and chemical stress while enabling sensor replacement and calibration in the running process. Thermowells offer particular advantages in tank applications, as the sensor can be replaced without having to empty the tank.
ifm offers a wide range of thermowells, also known as protective tubes, suitable for both hygienic and industrial applications.
Device replacement without downtime
Thermowells reliably separate the temperature sensor from the process medium. This makes it possible to conveniently replace sensors when necessary – even in the running process or during calibration.
Protection for temperature sensor
Thermowells protect the temperature sensor against mechanical, thermal and chemical stress. This increases operational reliability and extends the service life of the sensor.
Robust design for demanding environments
The robust thermowell design enables use under high pressure and in aggressive or abrasive media, ensuring a long service life even under demanding process conditions.
Application-specific designs
A wide range of thermowells is available for industrial and hygienic applications. Different process connections and installation lengths enable optimum adaptation to the respective process conditions.
Full-metal thermowells are constructed of one piece of stainless steel with no welds. Thanks to their compact design, they offer a very high pressure rating and are particularly suitable for applications involving high mechanical and thermal stress as well as critical process conditions.
Multi-piece welded protective tubes consist of multiple components welded together. They are typically used in applications with low to medium process loads and provide a reliable solution for many standard applications.
Image on the right:
thermowell (left) and protective tube (right)
- Process connector
- Metal tube
- Metal tip
Using a thermowell affects the response time of temperature measurement. The additional layer between the process medium and the sensor increases the response time compared with direct measurement in the medium.
However, this effect can be greatly minimised through the correct combination of temperature sensor and thermowell and proper thermal contact. Adding thermal paste will significantly improve heat transfer between the sensor and the thermowell and reduce the delay.
The response time (T09) for thermowell mounted temperature sensors will normally be in the range of:
- approx. 20 seconds when using thermal paste
- approx. 40 seconds without using thermal paste