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Calibrating hygrometers

Today I learned that one has to calibrate hygrometers. Hygrometers are used to measure the humidity of the air surrounding them. The measurements are not always completely accurate and differ over time.1 Therefore they need to be calibrated on a semi-regular basis of roughly 6-12 months. In the case of my analogue hygrometer, this is done by a screw on the back, but of course it’s individual per model. While there are various methods to do this, the easiest way I found was to take a wet towel and put the hygrometer inside. After 5-10 Minutes check the hygrometer, it should show 100%, if it doesn’t adjust it so it does. It’s not perfect, but works reasonably well and doesn’t need special tools or hours of preparation such as the salt test or one-time-use packages.

I came across that, when asking myself how they even work. I was aware of the rough concept but not all details. Therefore as an article for today, I decided to investigate it, and suddenly came across the fact that one should adjust them on a regular basis. As this might explained the unusual high numbers I saw on a regular basis on mine, recently, I took the opportunity and did it. I hope it’ll work out well.

Note: I urge people to go for good old analogue hygrometers. Not only do they look a lot nicer than their digital friends, but they also reduce waste as there is no reason to use batteries on those devices. And as long you just use it for regular home usage, an analogue one will do the job.

  1. Why exactly that’s the case, I wasn’t actually able to figure out, just that it happens.