You can get just about any reading you want depending upon where you place it. I measure humidity right at the surface of the soil. I'm not concerned about humidity a few inches above the soil, as the frog will never get that high in this enclosure. So if my soil is wetted, i'm reading a high humidity.

Cocoa fiber media can absorb quite a range of water. If I am making 'new media' and have soaked it, it'll take days before I have to spray it again. I usually wait until I see the surface drying out a bit. I also give it a stir to see how moist it is underneath. In a few weeks, you'll develop a 'touch'. I have a humidifier that is hooked up to a hydrometer and it helps keep a small part of my enclosure moist, but I still need to fuss with it a bit to make it perfect, sometimes it'll drench an area needlessly.

I think it is fascinating how little froggy drinks. Just buries itself in damp soil and over the course of a few days, it can soak up so much water that it appears comically bloated.