hygrometer - which one do i believe?

[Joey8765]

i have two hygrometers, one cost $50 which also has a temp monitor
the other one was like 5 bucks
they are about 20% different in humidity

the cat chewed the end off the $50 one but the humidity still goes up and down??

which one do i believe?

 

[CityGirlintheCountry]

Did you calibrate them? There is a process where you seal them up in a ziplok bag with a glass of wet salt. Whatever the salt/water combination is, the humidity is supposed to end up at 75%. Do google search for hygrometer calibration and see what comes up. I use two different units as well and they are 7 points apart.