I tested mine in a plastic bag with a pop cap full of salt paste and only got readings of 60% and 64%. I re-ran the test with a half-cup of salt, added enough water to make a paste and set it in a big Tupperware container. I have a wireless outdoor temp/humidity sensor and I placed that in there as well. The next morning they were higher all around 70% and after I got home from work they were all around 75% give or take a percent. I think the test may run better with more salt paste (1/2 cup) and a container similar in size to your humidor.
