[zBrinks]

General assumption: If you see condensation on the glass and it's a nearly sealed tank then it's safe to say humidity is close to 100%. I don't monitor humidity... It's mostly temps and you can buy a temp gun if you have multiple tanks

Just a side note - condensation on the glass is not a sign of proper humidity - that just means there is a decent temperature/humidity difference between the conditions inside the vivarium, and those of the room it is in.