However, it is highly recommended to check the hygrometer and if necessary to adjust the beginning.
The simplest check is to cover the hygrometer for a few hours with a wet rag is.
The Luftfeuchtigskeitsstand should be between 95-100%.
In my case, the needle was then vertically downwards. So I made an adjustment with saline.
The calibration is based on a chemical-physical principle: The Deliqueszenzfeuchte
About a saturated saline solution arises at temperatures between 20 ° -40 °, a humidity of 75% a.
So you take a larger or similar Tupperdose, glass bowl (Ideally transparent so that you can read the value without the container to open), this abundance with some water and cant enough salt to which this is
no longer dissolves in the water. Here you will clean the hygrometer, and covers the container airtight (cling film, etc.)
After about 4 hours is the humidity in the container exactly 75%, which should show a hygrometer also.
For you have to readjust after removing them hurry, because the hygrometer is very responsive. You should repeat the test after the adjustment until you get shown the precise 75%.
