Tube Resistance Thermometer TP 21 Hengesbach

The Tube Resistance Thermometers Type TP21 meet, by their design layouts, the requirements for a deadspace-free and hygienic measurement in all kinds of fluid media, like e.g. milk, beer, juice etc. The measurement occurs without a profile modification and without contacting the media by the sensing resistor, taking into account the good response times. Therefore e.g. cleaning procedures by a pig etc. are possible.

The device consists of a pipe body with neck tube in stainless steel. Integrated in the pipe body is a PT100-thermometer. Optionally the measuring insert contains one or two measuring resistors PT100, connected via the terminal block of the housing head in 2-, 3- or 4-wire circuit. The temperature sensors are to be integrated in the pipeline. Different connection versions for varying applications are available.


  • deadspace-free temperature measurement
  • no contacting with media
  • for food and pharmaceutical industries
  • entirely in stainless steel
  • corrosion resistance by field housing
  • custom-designed process connections
  • optional with transmitter


Housing field housing
Temperature sensor PT 100 acc. EN 60751, changeable measurement insert (Standard), insert tube 1.4571
Measurement insert, electrical 1 x PT 100 in 2-, 3- or 4- wire connection, standard: 1 x 3- wire connection, 2 x PT 100 in 2- or 3-wire connection
Electrical connection M16 x 1,5 – cable gland, MS nickel-plated,
Optional: M12 x 1 circular connector, 4-pins
Accuracy Standard: tolerance class A acc. to EN 60751,
Optional: tolerance class B 1/10, 1/5, 1/3, 1/2 DIN
Response time T50 (measured in water): 6 sec. (dependent on design, d = 6 mm) < 4 sec. with tapered sensor tip on request
Measured medium temperature Tmax at sensor = -20… +200°C
Housing material stainless steel 1.4301 (CrNiSt, standard-field housing)
Measuring section – material stainless steel 1.4571, optional 1.4435 or 1.4404, optional: tube in polished steel
Protection class EN 60529, IP 67 with cable gland, optional with cable connection
Pressure admissible PN = 10 bar
CE-conformity EMC-rules are fulfilled, CE-sign
Process Connection  TP21 / TW 59…T108, milk pipe screw joint with threaded double-sided neck, DIN 11851, DN20…DN100,
TP21 / TW 59…T141 , Tri-Clamp-connection acc. to ISO 2852
Other connections on request (please specify nominal width)
Neck tube: 38,5 mm x d = 16 mm (acc. to drawing)
Measuring section length: 120 mm (acc. to drawing)
Assembly components None
Electrical connection ceramic connection socket
flexible connecting wires
sheathed cable (shakeproof type)
transmitter TE 42, programmable, 4…20 mA, 2- wire connection (standard)
transmitter TE 41, programmable, galvanically isolated
transmitter TE 52, HART
transmitter TE 82, Profibus PA
Calibration factory calibrated, calibration certificate (3-point or 5-point), with DKD-standard
Certificates material certificate, acc. to EN 10204

Download Data Sheet: Tube Resistance Thermometer TP 21


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