Neat, a wooden bimetallic strip. For humidity rather than temp.Might be possible to rig it to throw a switch for a dehumidifier/humidifier.

I almost didn't click on this one. Why bother when I live in the Midwest, but after watching it makes me appreciate how much moisture affects my projects. Especially when you showed how quickly a boards dimensions can change.

In the local community college they have this panel on the wall that was glued up by a student years ago. He glued a board on the end grain (cross grain situation). They have screwed this panel to the wall on three of the corners and the third corner raises and lowers based on humidity. It is and example of not only how not to glued up a panel but also of what you have shown here. Very fun! Thanks for sharing! Chris

What a great conversation starter for the wood shop; and easy too. Thanks, Jack.

Wow this is so ingenious! I'm so totally going to make one of those! Awesome!

That's just neat, what a great idea and nice looking backer boards! Definitely sharing it on my FB page.

Very simple design. and it works like a charm. Thanks Jack, Roland

Jack, good stuff man! Very interesting and useful.

Excellent... I've never seen one before and I've learnt something, cheers

very nice, I especially like the look of the one that's similar to a piano

Boa explicação. Great explanation

Now I see why you made the big panel.

Just GREAT, thanks.

Thanks for a great video! Any idea if different Wood would be more or less sensible to humidity - e.g. pick up humidity faster and thereby "react" quicker? I guess spruce is one suggestion since it quickly "soak" up humidity?

Wow! That was interesting! Nice :)

Is there any particular species of wood that works best for this? Can’t wait to make one and compare it to my digital moisture meter.

I Love having things like my Blown Glass Barometer, and my Galileo Thermometer and I have been looking for a simple, real Hygrometer to add to my weather collection. would it be correct that the thickness of wood vs length is important? Longer and thinner means more accurate than short & stout? Would you consider making these for sale? I would love one, longer and thinner, to add to my weather collection. I fell in love with these years ago and used to give my Galileo Thermometers as housewarming gifts to real estate clients.

Great video...

Jack, I like your videos. I've often wondered how you cut a long piece of wood with your tablesaw so close to the wall. You always stop the video right when I'm about to find out. How do you do it?

Very clever.

Very cool

But you have the grain the wrong way. it should be flat sawn, not quarter sawn. You will get much more action that way.

The RH of those locations fluctuate hour to hour, day to day... it's the RH of those locations at the time of testing you should have written on the tape using the digital hygrometer as a reference.

umm, maybe a hygrometer? I see no way to use it as a hydrometer.