I don't think hygrometers are waterproof -- a search on Fischer Scientific came up with none, anyway. They need exposure to the air to get the reading, but the sensors are damaged by water. Dart frog keepers would have found a waterproof one if one existed, but they haven't.
Most people with racks will use an IR temp gun to spot check temps. In a rack, RH stays stable enough and keepers with that many animals can eyeball things usually (by looking at substrate moisture and condensation), but for the person who needs numbers a good device might be a handheld RH meter -- I've heard good about this one.
Honestly, in my 100+ tubs (no BPs, but a handful of species from rosies to rainbows) I don't typically even spot check temps unless some animal says they need a check (snake behavior is as good a thermometer as a digital one). You don't see this on YouTube, though; showing off some flashy tech thing is much more clickworthy than explaining how a cold snake is always on the hot spot, and a too-warm one is always hugging the front of the tub.
Reply With Quote