I'm looking for a temp and humidity gauge thats worth a damn. I've used exo terra's combo digital reader, Zilla's combination dial gauge, I've used the cheap stick on dials from the pet store. every one of them gives me different readings. Even the exo terra digitals; I've bought two, put them next to each other and they're like 20 degrees or 40% off. Who uses what, and where do I get it.