Where do you put the thermostat probe?

[Godzilla78]

I do what Cletus does, with one small hack...To simulate the plastic tub with heat tape below it, I have one empty space in my rack where a tub would be, I have a plastic tub lid laying on the heat tape and the probe taped to the plastic lid right above the heat tape area. This way I am simulating the temperature of the thin plastic tub right above the heat tape... just a tad more accurate than putting it directly on the heat tape itself.