While not directly related to the problem you were having here's an issue I was having until recently.
Don't know if its just me but Rod may want to add a note to the directions on the How To List. For if your battery is more than 1 year old start by changing the battery then continue with the Salt Test!
I use Xikar hygrometers and calibrated them as soon as I got them. Before I started using beads for humidification I was struggling with the damn floral foam system. Needless to say, I started to doubt the accuracy of my already calibrated hygrometer and decided to re-test them. The problem is, if you've already calibrated a Xikar and then re-calibrate it you'll really throw things out of whack and really not be able to get a good measurement. As it turns out, and I only found this out after re-reading the directions that came with the Xikar, if you are going to re-calibrate you should pull the battery to allow the unit to reset itself and then re-calibrate.
Absolutely the truth!!! Otherwise, lots of deviation.
I probably could have saved myself and Xikar a lot of heartburn by just re-reading the instructions before sending them back under their lifetime warranty. I will say that they took good care of me and exchanged them with no questions asked even though it ended up being user error.
I'll tell you.....both Xikar and Boveda have amazing reps. I have dealt with both extensively, and can only hope I rep my company as well as they do theirs.