Humidity in a 40G breeder

[sddragons]

I thought I would test the humidity so I bought a digital temp/humidity gauge. I can't even get it to register. Every now and then I see it display 38 or 40% but most times it is just blank. I tried spraying the tank down but it barely goes up. I have a 100W basking bulb on one side and a 24" Reptisum10.0 UV across the top. Temps stay around 80 on the cool side and not quite 100 under the basking bulb.
So how do you get the humidity up in a 40G glass tank with full screen top?

 

[NegativeCreep]

Could it be possible that you just got a bad gauge?

We couldn't keep our humidity high enough in our beardie cage, also a 40l, so we had to put in a cheap humidifier. But, you shouldn't have to do that, most don't have any problem at all. Try putting your gauge outside, see what it registers the outside humidity. If that doesn't register anything, its probably just a bad gauge..