Mix the salt and water in a small cup, stirring until totally saturated. After a few minutes, the mixture should resemble wet sand.
Place the cup and hygrometer in a resealable plastic bag. Keep the salt and the hygrometer completely separate.
Seal the bag and place it aside to sit at a consistent room temperature, away from drafts or direct sunlight. Let sit for 8 to12 hours.
Check the hygrometer, while keeping the bag completely sealed. In ideal conditions, the humidity should read as 75 percent. (Your hygrometer may be off by a couple of points.)
Remove the hygrometer from the bag. If you can, quickly adjust it to read 75 percent; otherwise, simply make a note as to how much you need to adjust your figure for each reading.
Things You Will Need
- 1/2 cup of table salt
- 1/4 cup of water
- Resealable plastic bag
- Before taking a reading, always try to give your hygrometer two hours to stabilize, so that it can register subtle changes accurately. You can use your hygrometer to be sure that the humidity in your home is low enough to discourage the growth of mold or to facilitate the storage of humidity-sensitive items such as cigars.