I'm trying to recalibrate my Hygroset II Hygrometers (two of them), and they are so darn touchy, they're harder than hell to set. I barely touch the thing and it jumps +/- 5-8 rh. I keep thinking if I can get one of them to the correct rh (75rh using the salt test), then I can use it to set the 2nd one. ugh..!