Kept the analogue gauge that came with my humidor for about 6 years too long. I knew it didn't work right (read 50%) I just never bothered to be too concerned as my sticks worked well. I have 70% beads in my humidor for several years and finally bought a new hydrometer in my last order from CI.
Calibrated it probably 5 times so far to get it "just right" (I'm a bit of a perfectionist). I did the salt method, using a small dish (about 3x the size of the recommended soda cap) and mixed the salt so that it wasn't dissolving or soupy - just more like a chunky paste. Put it in a bag over night, make adjustments and then repeat till it was 75% at 70 degrees.
Put the hydrometer in my humidor and let it sit for a few hours. Crack it open, expecting to see 70%...... Nope. 75% - WTF? I know for a fact that my beads are 70%, hell they don't even make 75% beads.
Beads are not over-hydrated, when I checked everything today about 1/2-2/3 of the beads looked hydrated while the remaining are 'white' indicating that they are dry..... If that's the case, why is my humidity so high?
Did I screw up the calibration by using a larger amount of salt/larger container? My sticks burn great....... I don't get it.
(If it matters, the humidor is stocked with about 60 sticks, is ~75% full. Kept out of sun light, keeps 68-70 degrees perfectly and has a good seal.)