Conflicting thermometer hygrometer

[C J]

I have had poor results with incubating. The last hatch 3 weeks ago was 24 very expensive Icelandic eggs with 4 hatched chicks (one died on day 3.) I've just gotten a new thermometer hygrometer with good rating - a ThermoPro TP50 Digital Hygrometer Indoor Thermometer.
It says I've got 70% humidity and 90 degrees F but the Little Giant incubator (with fan) says 60% humidity and 100 degrees. A food instant read analog thermometer says 108, but I think it reads high, remembering from when I checked it with boiling water. Not so sure what to do and I really hope someone can tell me whether to add water or not, raise temp or don't, etc. I have another thermo/hygrometer that I bought last year for and I'm sure the thermometer doesn't work on it, and if I find it and put it in there, I bet it will say something completely different.

Any advice at all for this hatch (in lockdown starting last night) or the next try?

Thanks in advance!!
CJ

 

[casportpony]

Have you calibrated using the salt test?

 

[C J]

Thanks. I'll do that for next time, I guess, since I'd have to take it out for 18 hours or so. I'll do it for hte other one and put it in the incubator quickly if I don't see any pips yet.