Invest in a digital hygrometer. Your cigars if you fill that humidor will much more than offset the cost of the hygrometer (maybe 20 bux?) and they're typically much more accurate. That's not to say they should not be checked/calibrated.
Here’s some good info from Lenny
Author: lenny4z Date: 02/06/2003 11:18 AM Reply
Oops, forgot to post the URL for the Salt test:
http://www.cigarsinterna...om/html/cig101_12st.asp