Hey everyone, hoping someone can help me out really quick.. I have both styles of resistor boards, both pre 1.1 and after 1.1 and with my pre 1.1 I never remember getting a resistor with it, or I promptly misplaced it as I did with my newer version one. My pre 1.1 PT-100 has been working for a year without the resistor, just the pt-100 hooked up to pins 2 and 3 and nothing at the 2nd pt-100 terminal. However when looking up directions on how to install my new one I noticed there's a resistor placed across the 2nd pt-100 terminal.. is it necessary and if so can someone tell me what the resistor is? I can only find instructions online where some users say less than 400 ohms, so maybe a 200 ohm resistor is good? Thanks for any help!
The resistor is provided to help you test the PT100 board. If you connect it between the middle 2 terminals as in your photo in place of a 2-wire PT100, it should give a reading of 0C. It is not used in normal operation.