Surface thermometers for different applications
Surface temperature measurement may be requested by industrial processes when hot surfaces of reactors or pipes have to be monitored and invasion into the pipe or reactor must be avoided. Temperatures of process streams have to be kept under control and regulated, sometimes even without any direct contact between the process medium and the temperature sensor itself in order to avoid any stream perturbation.
The SkinPoint thermometers, depending on the application, are installed in such a way that the detection point (located at the tip of the device) is kept in contact with the surface by means of welding, screwing, or clamping and if necessary it is even protected by customized shields.
In the process automation two measurement principles for temperature have asserted themselves as a standard:
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.
Suitable for high process pressures (no direct contact with the process)
Field of application in heavy duty industrial processes