I'm new here too, and trying to do all the research I can to make sure I can set up everything correctly. I understand OP was asking if a newer thermometer would be fine vs the accurite thermometer recommended in the 20g tank setup.

https://www.walmart.com/ip/Acu-Rite-...ndingMethod=rr


But that old thermometer actually has a 10ft wired probe for outdoor temps. It's separate from the wired probe for the thermostat. And it's getting difficult to find online now, which is why I'm in this thread.


The way the guide reads it suggests putting the accurite thermometer probe in the tank, on top of the the glass, with the thermostat probe outside the tank on the bottom of the glass. In this order.


Hide on the hotside
Substrate
Thermometer probe
Glass
Thermostat probe
UTH


That way the outside temp reading on the accurite thermometer would be the actual glass temp that your snake may come into contact with. The base unit on the accurite thermometer takes the ambient temperature and humidity from the cool side.

Even using an infrared laser thermometer gun, that's not going to read the glass temp, unless you remove some substrate, and your snake will keep messing that up.

Personally I was wondering about siliconing a wireless inside the hothide on its ceiling. It seems like that would be the closest a wireless sensor could get to the glass, without touching it, or sitting in substrate. Especially since any hide should be trapping heat inside thats rising up from the UTH, keeping it a little warmer than just outside the hide.