I have a moisture meter I've always used for woodworking, but I don't trust it for now staves, especially ones roughed out and I don't like driving pin holes in it anyhow.
I've set up a heat tube which is just stove pipe with a bulb in the bottom. A roughed out bow will drop about .02 ozs a day in it.
The question, if I leave the stave in until it doesn't drop (say 2 days in a row) is there any chance it will be to dry? Should it be more than 2 days, etc, etc?