Call Us +1-888-674-8307

Cigar University Banner

How to Calibrate a Hygrometer

Keeping your hygrometer working properly is vital. Without measuring proper humidity readings, your humidor may not keep the optimum humidity settings, and your cigars may dry out and suffer for it. Calibrating your hygrometer is the best way to guarantee that it is working properly and giving a correct reading. Before moving further, you should know that calibrating a hygrometer is done the same way whether you use analog or digital. Nice and easy. Now, let’s show you how to calibrate a hygrometer.

A lot of digital hygrometers will state that they are pre-calibrated in the factory. While they might be pre-calibrated, we still recommend that you calibrate your hygrometer before using it anyway. Really, it’s better to be safe than sorry. Taking a few hours to properly calibrate your hygrometer will save you from possibly ruining your stogies. Worth it? Totally.

A one-step calibration kit is one of the easiest ways to calibrate your hygrometer. The zipper pouches come with a humidity pack inside, which will always keep the pouch at 75.5% relative humidity. To calibrate your hygrometer, simply open the zipper pouch and insert the hygrometer in with the humidity pack, and then reseal the pouch. You will need to keep the hygrometer inside the pouch for at least eight hours. Some kits may require you to keep the hygrometer inside the pouch for 24 to 36 hours, but usually 8 to 12 hours is enough to get a proper reading. Do not disturb the pouch while your hygrometers are in there, or else you may throw off your reading.

Sale Price: $27.97

Your hygrometer should read either 75% or 76% (since most hygrometers don’t display halves of percentages). If the reading is correct, your hygrometer is properly calibrated. If the reading isn’t correct, you will likely need to adjust the hygrometer accordingly. Analog hygrometers can be adjusted by using the adjustment screw, often found on the back of the hygrometer. Digital hygrometers often come with an adjustment knob on the front. Once you are done adjusting the hygrometer, place it back in the calibration pouch for a few hours to see if it yields a proper reading of 75-76% relative humidity.

If you would rather not adjust your hygrometer, a cheat is to simply remember how far off the hygrometer is from the proper reading. Is it reading 70% when it should be reading 75%? Your hygrometer reads 5% low. You could use the hygrometer as is, so long as you remember to do the mental math in your head every time. Adjusting your hygrometer may seem like a pain but that pain only lasts the one time to adjust, as opposed to every time you read your humidity lever.

The one-step calibration kits are often reusable, so long as the pouch remains sealed between uses. You can test your calibration kit before recalibrating your hygrometer by pushing on the humidity pack. If it is still squishy, your pack is good to use. If it is hard, it has probably dried out, and will not aid in calibrating your hygrometer. If this is the case, get a new calibration kit.

When not using a premade calibration kit, your hygrometers can be tested by using a hygrometer salt test. The salt test can be done with common items found in your home.

Once your hygrometer is properly calibrated, you can place it back in or on your humidor.