#305 - How to wire a RTD probe to an RTD IO card

- Measure the resistance (in ohms) between the three RTD wires, e.g., 111 Ω between cores 1/2, 111 Ω between cores 2/earth, and 1.8 Ω between cores 1/earth.

- Check the wiring on both ends, sensor and IO card terminals. Note that core 2 is connected to earth.

Example of wiring from Allen-Bradley's 5069-IY4 card:

Example of wiring from Schneider's BMX ART 0814 IO card:

Note that these cards have an external cold junction compensation available with additional hardware.