Hygrometer calibration.

[Totemic]

How accurate are those calibration packets?
I ask because I've tried to calibrate my hygrometer (all digital) and either I'm doing the salt test incorrectly (although, I think I did manage to do it correctly once a while back) or there's something I'm missing.

I put a cap full of salt + some small amounts of distilled water (no more than a teaspoon if that, just enough to make a mushy mess with the salt) and stick it and the hygrometer in a ziplock baggy, making sure it's sealed completely.

Twenty four hours later, I come back and all the hygrometers are reading 71%. Initially I think, hey look at that, 4 hygrometers from 2 different vendors are off by the exact same amount.

I then take these hygrometers (which according to the salt test is -4%), and put them in with my "reference" hygrometer (see comment above about getting one of the salt tests to come out "right"--it was spot on 75%). Another 24 hours later and the -4% hygrometer and the "reference" hygrometer are all reading exactly 65% humidity in my humidor. WTF?

So I take all the new hygrometer out and do the salt test again. Repeat the same steps, make sure there's no air leaking out and then twenty four hours later, I see....71%.

So now I am in the following situation:

1. Either my "reference" hygrometer is off by the same amount (which means some how I managed to get my first salt test to reach 79% humidity).

2. Or I dorked up the salt test (most likely).

Being the anally retentive git that I am, I really want to figure out exactly how off these hygrometers are so I'm wondering if those Boveda calibration packets are accurate/reliable.

[mugen910]

To be honest..if they stay within +/-2 pts of the number on the calibration packet I'm content..

[SouthsideCigar]

I find the Calibration paks to be pretty accurate. I never liked using the salt test as the accuracy is dependent on how you make the salt mixture.

Dave