So I did the salt in the bottle cap with water slushy test for my Hygrometer and it is reading 83% even after I turned it all the way down. Is it safe to assume I should just add 8% to whatever reading I get or would it be in my best interests to get a new Hygrometer?
Yes it is a digital.
Do a search on RH and hydrometers and distilled water.
I don't trust the salt test - there are too many variables, mainly in how slushy you make the salt.
The Boveda calibration kit would be a good route.
What am I looking to find. I already did the salt solution test and it is reading high at 83.
It appears your Boveda at the bottom may be out of whack.
@IndustMech I have the exact same Rubbermaid container and the exact same hygrometers. This is how I calibrated mine also. Funny thing I noticed though. I let it set for overnight and in the morning the RH was 75 on all of my units with a 75% boveda pack in the box. I left them in there and when I came home from work, they were all reading 78%. Now which number do I trust?
Same. Temperature variances influence RH. If the next morning they are at 75 again and later at 78, it's telling you the universe is balanced and Boveda is good. You could also open the container for a few seconds, close it back up and wait about 15 minutes to see how well all of the hygrometers track, too. If they are all the same and within +/- 3 percent, I would call that a victory any day.