I built my PID controller so it's "convertible", as in, I can move from one furnace to another. The furnace plugs into a power receptacle that I put on the back of the PID controller box and the Thermocouple mounts to the pot, using a spring, just like a plain thermometer. That also allows placement of the TC tip nearest to the spout, where I want to know that temperature, moreso then elsewhere in the pot.