Hygrometer Calibration Pictorial

[rogatsby]

Thanks for the great tutorial. I know that baking soda is potassium bicarbonate. Does that work as well? I guess I could go out and get potassium carbonate, but almost everyone just has baking soda in their homes.

[Horus]

Thanks for sharing the tutorial. One thing that always bothered me about the calibration process is it only makes sure the reading is correct at one point (43%) and not across the entire range. I am wondering if there are hygrometers that allow broader calibration (3-5 points).

[KevinH]

Originally Posted by rogatsby

Thanks for the great tutorial. I know that baking soda is potassium bicarbonate. Does that work as well? I guess I could go out and get potassium carbonate, but almost everyone just has baking soda in their homes.

I believe "regular" baking soda that most people have is sodium bicarbonate. Potassium bicarbonate can be used as baking soda if you're avoiding sodium. I'm not sure what their humidity fixed point is.

Potassium carbonate is easy to get, inexpensive, and one of the few compounds that provides a fixed relative humidity (~43%) that is ideal for guitars. Amazon sells a pound for around $11.

[rampix]

Thanks to fjeff for resurrecting this thread and to Simon for posting it. I’ve only used table salt in the past but ordered the potasium carbonate. Testing in the range we’re monitoring seems more appropriate.