Another afterthought, motivated by other members’ experiences was to install some thermocouples to measure hearth temperature, both near the surface of the cooking floor, and at the junction between the floor and sub-dome insulation layer. As I could obtain only a six way selector switch for the digital temperature display, I opted to put four of the thermocouples in the cooking floor, and two in the dome. I wanted to ensure I could replace a thermocouple with a minimum of fuss (if I ever needed to), so I decided to make up some thermocouple housings which could be fixed to the steel decking. An instrument supply company provided 4 thermowells which had been made to the desired length, and I fixed these to cheap stainless steel mugs via a brass bush and back nut.
The ⅛" diameter thermocouple probes will be fastened inside each thermowell by means of a ¼" compression fitting, accessible from under the slab.
