I bought a cheap Amazon Calculated Industries 7445 AccuMASTER (affiliated link) that has both pins and pinless. I don't have much to compare it to except it seems to correlate to my perceptions of moisture content in various conditions, including when I've purposely dampened materials to test their drying over days. You do have to sink the pins maybe 1/8" or more to get a good reading. I don't have much confidence in the pinless readings. I'm using it for drywall, plywood, sheathing, and other construction materials in addition to solid wood.
The tone was a bit loud so I took it apart and hot glued the electronic speaker to be barely audible. And the on/off button is raised which caused it to turn on unintentionally in my bag (despite the 3-second hold-down requirement), so I whittled down the button's plastic so it sits below flush of the chassis. I'd want better from a quality device, but about what I expect from cheap imported online purchases.
Get a Delmhorst if you're using one for any serious/legal/official testing or reporting.
I was given some sycamore, mostly spalted, in return for building something fir a charity auction.
I plan to build a full size blanket chest and a smaller matching miniature one.
The wood was cut and stored inside since fall of 2019. Since I haven’t worked with sycamore, I don’t have a sense for what it should feel like if it is dry. Hence the need for a mm.
Update: I bought a General from Lowe’s and checked it today. It was measuring 12-15%. I just moved it into my shop. Most of the other stuff in my shop is showing 5% or less.
So, I guess I need to wait a little longer to work it.
Thanks for all the suggestions.