Measuring element, tolerance
For the model TF44 strap-on temperature sensor, WIKA uses the following measuring elements as standard:
- Pt1000, class B per DIN EN 60751
- Pt100, class B per DIN EN 60751
- NTC, R25 = 10 kΩ ±5 %
- NTC, R25 = 5 kΩ ±5 %
- NTC, R25 = 2.7 kΩ ±5 %
KTY and others on request
Platinum elements offer the advantage of meeting international standards (IEC 751 / DIN EN 60751). Due to material- and production-specific criteria, a standardisation of semiconductor elements, e.g. NTC's and KTY, is not possible. For this reason their interchange ability is limited.
Further advantages of strap-on temperature sensors with platinum elements are: better long-term stability and better behaviour over temperature cycles as well as a wider temperature range.
High measuring accuracy and linearity are also possible with NTC strap-on temperature sensors, but only in a limited temperature range.
This is set against the lower temperature sensitivity of platinum elements.