The probe for the tstat is in a groove in the melamine shelf under the heat tape. The wire below the probe is hot glued to ensure it stays put. The heat tape is taped down over top of said groove.
I measure temps with a digital temp gun and also have a distal thermometer with probe and another hygrometer/thermometer. All thermometers are within .5 of each other. I have had two bad thermometers so far and one of those was the first I ever bought. Caused me Freud with my Beardie in the beginning and now I double up on everything. I am just waiting for a second tstat for a failsafe. That is coming soon.
My tstat is set for 96.5 and this rack is in my living room with 72 ambient. I know that may be a little challenge but so far seems like it will work. The bottom tub is a little cool. 77 on cool side.