So I purchased a moisture meter to check a batch of wide plank flooring and subfloor to make sure moisture difference was <2% as per MFG. recomendations. The meter is a Wagner mmc 220. $400 OUCH!!!
In messing with this thing, I get all kinds of results. The meter is suppose to measure to a depth of 3/4", but when I suspend a 4/4" board above the bench, I get one reading, then set it down on the bench, I get a different reading. Also, if I measure the finished side of a board, then flip it over, I get a different reading. (Directions say you can measure finished pieces).
The meter has a species button which allows you to enter the specific gravity of the species you are testing , so you dont have to use any conversion to get a correct reading, However, the table lists so many different types of each species of wood, I don't know which one to pick. ie. I am testing hickory flooring, but there are 8 species of hickory listed, with each one having a different specific gravity. How do I know which one to use? (there are 11 different red oaks listed in the table!)

Same story with maple, I have several pieces of "hard" maple. There are 7 species listed in the table.
I have some maple that is "case hardened" and has terrible tension release when cut. I also have some slow dried maple that works like a dream. Both samples test out about the same for moisture.

So other than monitoring the progress of drying wood, what is the value of a moisture meter to the average woodworker, and how can you trust the readings you get?