A hygrometer is a device that measures relative humidity.  In photography, we use the hygrometer in a dry box to make sure that the humidity measures between 40-50%, thus dry enough to deter growth of fungus or molds in our lenses, sensors.

I just found out that the hygrometers sometimes give inacurate readings, thus, the need to calibrate them before using it.  I was given a link by a friend and member of the Photographic Society of Iloilo, Paul Go, on how to calibrate a hygrometer.

I hope you’ll find this useful… How to Calibrate a Hygrometer

Other related topics… Do-It-Yourself Drybox