Thermowells & protection tubes
Thermowells & protection tubes for temperature sensors in different industrial applications
The thermowell is the process wetted part of the thermometer. Basically, thermowells are divided into protection tubes constructed from welded tubes and thermowells made of drilled barstock material.
In many cases thermometers cannot be placed directly into the medium but need protection from rough process conditions. Furthermore the thermowell makes sure that an exchange of the measurement insert is possible without interrupting the process.
RTD – Resistance temperature detectors: Measuring principle
The RTD sensor changes the electrical resistance with a change in temperature. They are suitable for the measurement of temperatures between -200 °C and approx. 600 °C and stand out due to high measurement accuracy and long-term stability. The sensor element most frequently used is a Pt100. As a standard, Endress+Hauser RTD sensors fulfill the IEC 60751 accuracy class A.
TC – Thermocouples: Measuring principle
A thermocouple is a component made of two different metals connected with each other at one end. An electrical potential (thermoelectric force) is caused due to the Seebeck effect at the open end if the connection and the free ends are exposed to different temperatures. With the help of the so-called thermocouples reference tables (see IEC 60584) the temperature at the connection (measuring junction) can be concluded.
Thermocouples are suitable for temperature measurement in the range of 0 °C to +1800 °C. They stand out due to the fast response time and high vibration resistance.
- Increases the life cycle of the measurement insert through protection against process influence
- Possible measurement insert exchange under process conditions
- Mechanical stability against pressure and flow