Maggie Evans 
A hygrometer is an essential component of your cigar accessories. All cigar enthusiasts will agree on the importance of storing cigars in a favorable, humidity-optimized condition.
But, you have to understand how to calibrate your digital hygrometer to get the most use out of it. You want to ensure you get the most accurate readings to help you monitor the humidity levels to preserve the quality of your cigars in their humidor.
A hygrometer alerts you when it is time to replenish the reservoir by reading the humidity levels. When the humidity goes below 65%, it is advisable to refill and take it back up to the ideal 70%.
It is important to note that the humidity levels and other conditions in your humidor will fluctuate depending on the number of cigars you are storing, the climate in your area, and the season at the time.
On this note, if you fail to calibrate your hygrometer, you will not know whether or not the humidor is maintaining the right conditions for the quality of your cigars. The readings will be faulty, which will result in damage to your cigars if not addressed on time.
So, how do you calibrate your hygrometer?
Using the Salt Test
The salt test is a common method of calibrating hygrometers, thanks to how easy it is to do and the fact that you do not need to assemble an entire kit to calibrate your hygrometer. Also, this test has shown to work on most hygrometers; therefore a safe route to take as a beginner.
Here is how you can calibrate your hygrometer using the salt test.
Get a clean plastic bottle cap from any bottle at hand. This could be a bottle of water, soda, or juice. Clean the bottle cap and rinse it out thoroughly to clear any product. Dry the cap and pour a teaspoon of salt into the cap.
Next, add a few drops of water to the salt, just enough to saturate the salt and not dissolve it completely. You should achieve a pasty mixture.
Get a Ziploc bag and place the bottle cap inside the bag with the hydrometer. Zip the bag up and ensure the seal is tight.
Leave the bag in a safe place to sit for about 6 to 8 hours. After this, note the readings of the hygrometer before opening the bag. The hygrometer should be at the 75% reading. If note, you will need to adjust the reading to register 75%.
If using an analog hygrometer, adjust the needle to read 75% on the gauge. Use a screwdriver and turn the screw at the back of the hygrometer. If you have a digital hygrometer, use the tune button to adjust the reading.
This is all you need to do to get an accurate reading on your hygrometer once back in your humidor. Test it by leaving it in the humidor for several hours before taking the first reading. Take note of the reading when you first open the box to ensure accuracy.
