The hygrometer is a fundamental accessory for the correct conservation of cigars. It is used to measure the humidity inside our humidor and it is therefore very important to be able to trust its measurements.
Often the hygrometers that are supplied in “cheap” humidors are more decorative than functional tools and this is a big problem, as there is no effective control over humidity.
WET TOWEL METHOD – USELESS !!!
Many use the wet towel method to control if the hygrometer works. This is a quick solution, but the only indication it gives is if the dial of the hygrometer (in case of an analog hygrometer) or the number (digital hygrometer) reaches 99%. To get the same result, you can just breath on to the hygrometer, like it is often done when you wipe a pair of glasses. Same result, without the use of any wet towels! That being said, this is NOT a valid method to verify if hygrometer functions correctly or not.
The movement of the dial or the change of numbers are not absolutely synonymous for a correctly working hygrometer. There is another, correct, method to calibrate the hygrometer : the salt and water method.
SALT AND WATER METHOD
To calibrate or check the hygrometer works correctly, you need :
- a coffee cup (or another small container)
- an hermetical container
Take a coffee cup and fill half o fit with salt. Add a few drops of water and mix it, until it reaches the same consistency of wet sand.
Then, put the hygrometer and the cup, with the salt and water mix, in an airtight container. The container is closed for at least a couple of hours. The hygrometer will have to record exactly 75% of humidity.
The difference in percentage indicates how incorrect the hygrometer is. In case of only a small difference (2-3%) you can just simply mark it on the hygrometer, this way we are reminded how much it differs. If there is a huge difference, the problem lies with the hygrometer. In this case we suggest to change the hygrometer.
There is a Boveda Kit available, which controls the correctness of the hygrometer. It is an efficient and simple method, that only requires a couple minutes: you just need to insert your hygrometer into the kit and after a few minutes you can verify how accurate it is.
This Kit can be used multiple times and with multiple hygrometers at the same time. You just need to close it correctly.