Here’s a quick tutorial on something you might have been wondering about.
To calibrate your hygrometer you will need: table salt, a transparent container that is capable of being sealed (a Ziplock bag will do just fine), and another shallow cup or bowl.
Figure 1: Hygrometer
- Put a teaspoon of salt in the shallow cup or bowl and add a few drops of water. (But not enough to dissolve the salt).
- Shake the damp salt into your see-through container and then insert the hygrometer. Close the container tightly.
- Let the damp salt sit in the sealed container for at least 6 hours, keeping an eye on the hygrometer without opening the container. The hygrometer should be at 75%. If it’s any less or any more, the difference represents how many points you need to add or subtract. (So, for example, if your hygrometer reads 65%, you will need to add 10 points).
- If you’re working with an analog model, simply adjust the needle by turning the screw on the back of the device to make sure the device is set to 75%.
- Remove the hygrometer from the see-through container and place it back inside your humidor!