#93: In-line pre-calibrated transmitter for easy, reliable installation

Model t/c.XMTR- * - ** 4-20 mA Transmitter

Current loop transmitters for thermocouples have traditionally been designed as “hockey pucks” in order to fit thermowell heads, thus complicating installation for applications not using a thermowell, and requiring a housing for protection. Additionally, they generally have to be calibrated to a specific range, usually with thermocouple simulators or other such device, thus requiring significant set up time and the possibility of unauthorized recalibration.

The t/c.XMTR is designed to overcome both of the costly inconveniences:

  1. In-line design is only slightly larger than the cable and requires no mechanical support.
  2. Precalibrated for thermocouple type and temperature range eliminates all adjustments, requirements for simulators, etc.
  3. Hermetically sealed stainless steel construction is suitable for the harshest service without any additional packaging.

The t/c.XMTR is specifically designed to interface to any model IRt/c (or any conventional thermocouple) by a simple thermocouple connector or splice. The 2-wire current loop can be used in any conventional current loop circuit that is scaled for the temperature range of interest.

Model Selection

  1. Select the correct IRt/c model for the application: target temperature, target material, field-of-view.
  2. Select the t/c.XMTR model for the t/c type and temperature range from the table below. Example: t/c.XMTR-K150 


  1. Install IRt/c as normal.
  2. Connect IRt/c output cable to the thermocouple input side of the transmitter using standard t/c connector, splice, or other standard method of connecting thermocouple cables. Transmitter should be located in a an environment no higher than 70°C (158°F) in temperature. Additional t/c extension wire may be added as required. Use of twisted shielded t/c wire is recommended (same as on the IRt/c and transmitter), and maintain shield connections.
  3. Check load on transmitter and power supply voltage for correct range (10 VDC minimum @ 10W; to 22 VDC minimum @ 1KW).
  4. Set readout device (controller, computer, PLC, etc.) for 4 to 20 mA range to match the t/c.XMTR model range.
  5. Perform final calibration of IRt/c installation in accordance with IRt/c instructions, using offset on current loop readout device.
  6. Installation complete

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