Help. What hydrometer/thermometer do u reccomend for an incubator?

I am currently running a test on an incubator I built. I am having issues with hydro meters and thermometers I got four of the digital ones off eBay, the problem is I am getting readings as follows on them 87, 93, and 105. I know they are off according to my temp gun but I want some that actually work. They all are showing humidity of 99%. Anyone have any recommendations for good ones? Or is the problem that I have the displays in the incubator? They are not in the egg boxes that have the humidity just sitting on top of them. Any help is appreciated as I should have eggs in the somewhat near future.