I need humidity help, please :)

My 65 gallon emp. tank is at only around 60% humidity and the temp is at 80-85 depending on the time of day. I have a false bottom setup and a 75w infrared heat bulb about 18 inches up from the substrate. I'm considering adding live plants to the tank to increase humidity. The top of the terrarium is enclosed. I'm not sure what else to try. Any suggestions?

Where is your gauge.....because by the sounds of your set up, you probably have more humidity than your tank is actually telling you.

Somewhat near the top. I will try moving it down but I do not believe it will go up as much as i'd like it to.

Do you have a screen top or plastic cover?

Plastic. I got the temp to raise to 85 and the humidity to 70% with the light. It's doing better.

The humidity sounds fine to me. Remember, the scorpions are on the damp ground and in their burrows (if yours have any) most of time. The humidity at the top will differ from the ground, especially in their burrows. Not to mention that most gauges are incorrect which is why I don't even bother with them anymore.

All I do is dump water onto the substrate every now and then. I make sure that the entire substrate is evenly damp, but not wet and everyone has been going well so far.
Adding live plants is a good way of increasing humidity--I suggest pothos plants as they do pretty well in tropical enclosures.

I woke up and checked everything. 78F and 85% humidity at the bottom, assuming the meter is working.

which it probably isnt. as long as the ground is damp and there is water in the false bottom its not going to be low.

Similar to what has been said previously, if you are doubting the humidity level, then simply pour some water onto the substrate so that it is damp but not soaking and that should give you about 80%-90% and last for a week or two.

humidity is perfect now. its maintained 85% all day.