Thermocouple Cables Specifications

Research "Seebeck effect".

If you are going to remote connect thermocouple cables, and want any accuracy, you MUST maintain the thermocouple wire type and connector material to match the thermocouple type. By type I mean B,C,D,E,J,K,N,R,S,T. The temperature range is what determines this.

If you try to splice different materials, each junction will induce a voltage, at the location and relative to the temperature of that joint and material.

You also have to include cold junction compensation. This can be done by the electronics used to convert the microvolts to a temperature scale of choice.

You have some learning to to do. This stuff is not taught in engineering course work typically, and has some domain experience to learn the DOs and DON'Ts.

ignator

There are two conventional means of getting thermocouple temperature data:

1) Thermocouple direct

Components:
- thermocouple
- thermocouple extension wire to connect thermocouple to the analog input card. Extension wire type must match the thermocouple type.
- analog input card must be capable of providing cold junction compensation (it is if it takes thermocouple direct). Not all receiver/devices can handle thermocouple direct.

2) Temperature transmitter

Components:
- thermocouple with a short lead of thermocouple wire, connects to transmitter
- temperature transmitter which has an analog input that takes thermocouple mV, does cold junction compensation, converts to temperature units, exports data as a 4-20mA current signal
- power supply for the temperature transmitter, typically 24Vdc
- copper wire to connect transmitter to receiver
- receiver (PLC, DCS, RTU, controller, recorder, indicator) analog input that can handle a 4-20mA current signal.