hygrometer and humidity

[mulia24]

I just making an incubator, and after search for one week (that's not easy to find this thing in my country especially my region). I found it, I bought 2 hygrometer, 1 is analog, another is digital, and I try to calibrate the digital one by using salt and water mixing. 1/2 cup of salt and 1/4 cup of water (even the salt can't melt perfectly). after put it into plastic closed tightly for hours I find the humidity still in 70% and 31%. this hygro is made in Germany and cost me about (if converted to $US) $45. what an expensive device for me. when still in "ordinary air", analog one showed 70% and digital one showed 65%. I haven't put the analog one into "salty plastic bag". note: the hygro didn't touch the water and two of the hygro show the same temperature (they're thermohygrometer)

what I am asking for is did my thermohygrometer broken? how do I fix this problem?
could I incubate and get high success rate in hatching without using/counting the hygrometer/humidity factor?
could I incubate and get high success rate in hatching without counting/using thermometer/temperature factor?
in case my eggs are fertile.

please forgive me if the question too long, that because I'm still a newbie in poultry. also forgive me if there are syntax or any grammar problem cause English isn't my mother language.

 

[Junkmanme]

Mulia 24,

IF I understand correctly, since your digital hygrometer shows 70% when it should show 75%, then if you add 5% to your readings, it should be reasonably close to actual humidity.

ALSO, the analog hygrometer MIGHT HAVE a "screw" on the back to adjust it. BUT, you said that you haven't tested the analog one. Perhaps you should test the analog one in the bag of salt and water also.

As I understand, the humidity can vary much more than temperature and still be fine. TEMPERATURE should not vary much. Especially NOT WARMER than 103 F ( 36-37 C ?). Temp should stay at 100 F (35 C ?), I believe.

Others here can correct me if I'm wrong on any of this.

-Junkmanme-