A hygrometer is a gauge that is used for measuring the humidity level. To measure the humidity levels inside cigar humidors, you can use digital or analog hygrometers. Compared to analog hygrometers, digital hygrometers are more accurate and reliable, read more at Cigar Cigar Info.
But no matter what kind of hygrometer you have, the important thing is to maintain a humidity level of 68% to 72% inside a cigar humidor to properly preserve and age them. To monitor and adjust the humidity level of the humidor, the reading of the hygrometer should be more or less accurate(+/- 2%).
Most of the analog hygrometers are manufactured with a tolerance of plus or minus 4 to 5% or more of humidity in the range of 40 to 80%. Though the humidity gauges are pre-set in the factory, it is not unusual if you find the calibration off when you get home and put it in your humidor.
If you want to check how accurate your hygrometer is, then you can do a simple test using things that you can easily find in your kitchen.
How to Test and Calibrate a Hygrometer
1. Take a bottle cap or any small container and fill it with salt. Now add a few drops of water but not enough to dissolve the salt.
2. Now place the salt in a plastic bag or container with your hygrometer and seal it.
3. Wait for 6 hours, now check the reading on the hygrometer without opening the container or bag(or immediately after removing it). If the reading is 75%, it means your hygrometer is accurate and requires no adjustment.
4. If the reading isn’t 75% precisely, adjust the hygrometer to 75% by turning the dial or screw at the back. This has to be done immediately after removing the hygrometer from the bag or container before the room conditions can cause any changes to the reading.
If your hygrometer does not have any dial or screw to recalibrate, then you can just add or subtract the difference between 75% and the test reading, to determine the actual humidity level in your humidor.
For example, if the test reading of your hygrometer is 80%, subtract 5% from the readings that you get inside your humidor, to determine the actual humidity level (for example, if the reading of your hygrometer inside the humidor is 70% than the actual humidity level is 65%).
You can also test your unit by wrapping the hygrometer in a warm and damp paper towel for around 30 minutes or till the reading is 80 to 90% plus or minus a few points.
Testing and Recalibrating
The bottom line is, you must test your hygrometer at least once in a year and recalibrate it if necessary. If you have invested in a good humidor, then do not risk the improper aging and storing your cigars by relying on a faulty or cheap hygrometer.
A good and properly calibrated hygrometer will help in maintaining a healthy environment for your cigars.