I've read before how to test the accuracy of your hygrometer before but have never done it and can't remember how it said to do it. Something about salt in a bag.
I've just always tested them against each other figuring if they were close to each other they were probably coorect. I recently took all mine out and set them in a drawer with some others I dont use. I later noticed that of my six digitals, 3 were all about the same at one setting, and the other three were all about the same but 5 percent lower then the others. This half and half split seems very odd to me but now that I have noticed, it still remains the same.
I've just always tested them against each other figuring if they were close to each other they were probably coorect. I recently took all mine out and set them in a drawer with some others I dont use. I later noticed that of my six digitals, 3 were all about the same at one setting, and the other three were all about the same but 5 percent lower then the others. This half and half split seems very odd to me but now that I have noticed, it still remains the same.