ATEX Exd Resistance Thermometers

Atex Exd Thermocouple

Resistance Thermometers with Ignition Protection Exd

These immersion and insertion resistance thermometers comprise a rugged installation fitting made of stainless steel with thread, flange or weld-on connection, a cast aluminium connection head, and a removable measuring element. The insert can be replaced without emptying the installation, because the customised thermowell remains in the installation and seals the process. The instruments are supplied with ignition protection Exd as standard so can be installed in relevant hazardous areas.

A 2, 3 or 4 wire Pt100 rated to IEC 751, category A or B is fitted in each measuring insert. Alternatively, the 2 or 3 wire versions can be designed as a single or double Pt100 thermometer. Optional head transmitters, encapsulated in epoxide resin inside the connection head, are available to transmit measuring signals noise-free over long distances, with either a  4-20 mA signal , or with HART® protocol or PROFIBUS®/Fieldbus.  The immersion length, connection head, materials, process connection and tolerance classes can all be customised to meet your requirements.

These resistance thermometers with thread-, flange- or weld-on connection are ideal for temperature measurement in liquids, solids and gaseous media. The reliable water tightness of these installation methods is critical when dealing with gauge pressure and vacuum.  Applications include the air-conditioning and cooling industry, and heating-, furnace-, mechanical- and apparatus-construction. Supplied with ignition protection Exd, these ATEX Exd resistance thermometers are perfect in hazardous areas.

This ATEX Exd sensor is also available as a thermocouple.

Please ask for more information.


  • Measuring range: -80°C to +600°C
  • Pt100 2, 3 or 4 wire: Insertion and Immersion, Class A or Class B
  • Output: Resistance or Analogue 4-20 mA
  • Thermowells: up to 1000, 3000 respectively 5000 mm (depending on model)
  • Option: head transmitter with HART®-protocol or PROFIBUS®/Fieldbus, display
  • Connection: thread, flange, weld-on sleeve
  • Bulb Material: stainless steel
  • Applications: ATEX, ignition protection Exd

Technical Data

Measuring Range: -30ºC to +500 ºC or -80ºC to +600 ºC (others on request)
Sensor: Pt100 Single or double sensor (1 x Pt100 or 2 x Pt100)
Accuracy: Class A or Class B (others on request)
Ambient temperature: -40 … +150 °C with ceramic terminal base (without transmitter)
-40 … +85 °C (with transmitter)
-20 … +70 °C (with LCD display)
-20 … +80 °C (with LED display)
Operating pressure: up to 250 bar (depending on thermowell)
TWL-1: low pressure
TWL-3 and sensors without thermowell atmospheric temperature
Connection head: form XD with chain (no chain with optional display)
Cable entry: M20 x 1.5 standard (others on request)
Materials – Sensor: stainless steel 1.4404
Materials – Thermowell: stainless steel 1.4404 (others on request)
Materials – Neckpipe: stainless steel 1.4404
Materials – Connection head : aluminium, painted
Materials – Terminal base: ceramic (without transmitter)
Process Connection – Thread: G ½ male, G ¾ male, G 1 male, ½” NPT, ¾” NPT, 1″ NPT
Process Connection – DIN-flange:  DN 15, 20, 25, 32, 40, 50
Process Connection – ANSI-flange:  ½”, ¾”, 1″, 1½”, 2″
Process Connection – Weld-in: ¾”, 1″, 1¼”
Sensor wiring: 2, 3 or 4 wire
Output: resistance value
Protection: connection head IP 54 … 68 depending on cable gland and
sealing sensor IP 68
ATEX-approval: Ex II 2 GD Ex d IIC T6
Head transmitter – Output: analogue output 4-20 mA
Head transmitter – Communication: HART®-protocol, Profibus®/ Fieldbus
Head transmitter – Minimum meas. span: standard transmitter 25ºK
transmitter with HART® 10ºK
transmitter with Profibus®/Fieldbus 5ºK
 Head transmitter – Supply voltage: 8 – 35 VDC for standard transmitter and transmitter with HART®
9 – 32 VDC for transmitter with Profibus®/ Fieldbus
Display – Type: 4 digit LCD or LED
Display – Supply: loop powered
Display – Voltage drop out: LCD max. 2.5 V
LED 3.3 V at 4 mA
3.7 V at 20 mA