TR21-A Resistance Thermometer

The WIKA Resistance Thermometer Model TR21-A provides temperature measurement in sanitary applications and can be used for the measurement of liquid and gaseous media in the range of -30 ... +250 °C (-22 ... +482 °F). For application in hazardous areas, intrinsically safe versions are available.

These thermometers are fitted with thermowell's, whose process connections meet the stringent requirements, regarding materials and design, of hygienic measuring points. All electrical components are protected against moisture (IP67 or IP69K).

The resistance thermometer is available with linear sensor output or integrated transmitter, which can be configured individually via the PC configuration software WIKAsoft-TT. Measuring range, damping, error signaling per NAMUR NE43 and TAG no. can be adjusted.

For easy calibration or maintenance, the sensor is removable without having to break into the process or disconnect the electrical connection. Thus hygiene risks can be minimized, and downtimes can be reduced.

The spring loading, integrated into the union nut, guarantees the contact between the sensor tip and the bottom of the thermowell and thus ensures a short response time and lasting, high accuracy. The welded junction between the thermowell and the flange makes the use of sealing as additional material in those areas redundant which are in contact with the product.

Insertion length, process connection, sensor and connection method can each be selected for the respective application within the order information. The electrical connection is made via an M12 x 1 circular connector. For applications requiring the sterilization of the instrument in autoclaves, an especially temperature-resistant instrument version is available.


  • Sensor can be calibrated without having to open the process
  • Compact design for space-saving fitting
  • Simple and fast electrical connection via M12 x 1 plug connector
  • With direct sensor output (Pt100/Pt1000 in 3 or 4-wire version) or integrated transmitter with 4 ... 20 mA output signal, individually parameterizable with free-of-charge WIKAsoft-TT PC configuration software
  • Materials and surface finish quality by standards of hygienic design

Customer Service

Edward van Doorn