Most of the inexpensive moisture meter are calibrated for furniture grade wood. the little bit better ones will include a chart by species for readings, some may even be recalibrated most not. better meters are in the $60-100 class best above that yet. Most are not built strong enough to get beyond 1/4" penitration. you can make your own pins from a couple nails and a piece of thick plastic, keeping the spacing between the pins the same as oem. then pound those in and touch meter pins to those. Note , as was stated before, all reading should be done at room temperature. There are calculations to adjust for lower temps. The better meters may have something built in or a chart/ graph included with them. bit tecnical but that's the scoop.