The Boveda One Step Calibrating Kit can be used to calibrate any digital or analog hygrometer. The kit includes a humidity pack that generates exactly 75.5% humidity. Simply tear the seal open on the humidity pack – it will then open just like a zip lock bag. You can then place any amount of digital or analog (or a mix) hygrometers into the pouch. Then you’ll just reseal the bag and let it sit.
The humidity pack inside of the pouch will make the entire contents of the pouch exactly 75.5% humidity. So you will be able to tell how accurate your hygrometer is compared to the 75.5 % humidity level of the controlled environment in the pouch. If the hygromter does not read 75% or 76%, you can then adjust your hygrometer accordingly so that it is accurate. For best results, leave your hygrometer(s) in the bag for 24-36 hours.
When you’re done calibrating, you can remove the hygrometer(s) and reseal the bag for future use. You’ll know that that the kit will still work correctly over time if the humidity pack is soft. If the pack becomes hard and dried out, you’ll have to discard the calibrating kit.