i see no way to calibrate my hygrometer, I have done the salt test and it reads 71% though. it is a digital unit from Cigars international called digital hygrometer #1
here is a link, let me know if I am able to calibrate it but I have looked very hard for some type of sdjudtment on it.
http://www.cigarsinternational.com/p...ext=hygrometer the local humidity right now is pretty low, i think in the low 40's.