Can anyone recommend a good hygrometer? I thought I was having issues with my humidifier cause it never seemed to go over 39%, so I decided to "calibrate" my hygrometer. I initially got a analog one from a pet store. It went up to 75% using the salt water in a bag technique, but from these forums I learned they tend to get stuck on 40% and you think everything is fine, etc, etc. I then got a digital and like I said, it doesn't go over 39% in my room. Calibrating it, it only went to 58%. Can it really be off by that much? Anyway, don't know if I should get a new one or just assume my rh is fine.

Oh, I have the Philips AJ260 Weather Station Clock.

I have this one made by Holmes, which I've had for a few years, and I like it so much that I just bought 2 more:

Holmes hygrometer

BTW: I'm not sure I got it from that seller.....I just posted the first seller that I found on google search.

If you are only looking for a reference for your hygrometer then you might want to get a sling psychrometer. Commonly available ones run from $10-100 depending on the quality and ease of use. Psychrometers measure the dry and wet bulb temperature from which you can calculate the relative humidity. If you are a DIYer or a home scientist you can make your own with two bulb thermometers, some gauze, and either a sling to spin the thermometers with or just a small fan. You would then need to get a chart for determining RH from the readings, probably readily available online.