So quick question regarding general measurement of temperature within a snake enclosure. Snake/enclosure in question is a Dumeril's in a 20 gallon long. UTH on right-hand side, controlled by a HydroFarms thermostat (I know not the best, HerpStat will come once I'm out of grad school and have more disposable income). Supplemental temp measurement by one of those small digital reptile thermometers.

My question is, where should I be placing the probe to measure the temp? For instance, many Dumeril's care guides recommend a lower temp range due to their natural habitat: 80-85 hot side, 65-75 cool side. Should that 80-85 be measured directly over the UTH, or right on top of the substrate? He does burrow, but it's 50/50. I just worry that pegging my UTH at 85 may lead to a too-cool enclosure, even if I do jack the heat in that room.

Just wanted to see what the rest of the community does regarding temp measurements in context of recommended temp ranges, species notwithstanding.

Thanks!