Dual Thermocouples ???

[donafams]

id like to split my 6' high over in half with a insulated shelf in the center to use the bottom area only for smaller things.. my thermocouple is mounted up higher above the shelf, if i mounted a second thermocouple in the lower area how would i connect it to the controller?

[CarWiz]

Use a double pole double throw (DPDT) switch to select the TC. This could pose a problem though if the TCs are a little off in resistance between them. The PID can be calibrated for a particular TC but switching between two could throw the PV temp off a little. Try it and see if it works. The worst case is that one may read a few degrees different.