Firstly, here's a pretty good video on the salt test. My test box is pretty close to the dimensions of the box used for this test. Video is a little long winded, but you get the science and process. I'll post the link to the video on Youtube instead of posting the video in this post. https://www.youtube.com/watch?v=aeLPRZQTA4w


Personally, I've been in the Boveda 75% calibration pack camp for quite some time, but I've always wondered how close those packs are to a real salt test.

The nice thing about the Govee units is you can really monitor what's happening over time, in real time on your phone. I started the 4 unit calibration group test below on Sunday and they finally stabilized earlier this morning. (Wednesday) Overall accuracy was probably the best of any Govee group I've worked with previously. None of the units required more than a few tenths of adjustment to RH. My calibration target was 75.5 RH at 70 degrees F. Unfortunately, I wiped the data before starting my second test using a 75% 60 gram Boveda pack. From experience, I know the air in my test box will stabilize in 24 hours or less with the larger Boveda. The Bovea pack just has more surface area in contact with the air so it works faster than a tiny dish of salt.

My goal is to make a determination on which calibration media I will use going forward. Time is not an issue so salt will be fine as long as it offers better accuracy than the Boveda packs. I do my calibration testing in a small Sherman travel humidor. I have no doubt this box is air tight.

Early indications tell me the salt test provides a better 75.5% controlled humidity environment than the 75% Boveda pack. Some of the salt calibrated units have crept above 75.5% RH in less than 3 hours since starting the Boveda test. When the RH readings from all 4 units stop increasing, I'll know the test is complete.