I understand that humid air is generally lighter than dry air, as water vapor molecules are lighter than nitrogen or oxygen molecules.
But... my issue is that when I test RH in a closed container (a cigar humidor), the RH is always 4 - 6% higher at the bottom.
I have verified my hygrometers are calibrated and tested this using multiple humidors and multiple hygrometers to ensure accuracy.
I live in Colorado and figured the high altitude may have something to do with it. Or is it that in a closed container, the displaced nitrogen and/or oxygen molecules have no where to escape.
Not sure why this would be.