WIKA Miniature Resistance Thermometer (TR21-A)

For sanitary applications, with flange connection


  • Sanitary applications
  • Food and beverage industry
  • Bio and pharmaceutical industry, production of active ingredients

Special features

  • 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 parameterisable with free-of-charge WIKAsoft-TT PC configuration software
  • Materials and surface finish quality in accordance with standards of hygienic design

Sales Contact (Wika.sales@asyatrafo.com)




The model TR21-A resistance thermometer 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 use in hazardous areas, intrinsically safe versions are available.

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

The resistance thermometer is available with direct sensor output or integrated transmitter, which can be configured individually via the WIKAsoft-TT PC configuration software.
Measuring range, dampening, error signalling per NAMUR NE 043 and tag no. can be adjusted.

For easy calibration or maintenance, the sensor is interchangeable without having to open the process. Thus hygiene risks can be minimised 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 protection tube and thus ensures a short response time and lasting high
accuracy. The welded junction between the protection tube and the flange makes the use of a 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 ordering information. The electrical connection is made via an M12 x 1 circular connector.

For applications requiring the sterilisation of the instrument in autoclaves, an especially temperature-resistant instrument version is available.