Wood Moisture Meter
Knowledge Center

Pin-type wood moisture meters use sharp pins that act as electrodes. When inserted into the wood, they send an electrical current through the wood to each other and use the amount of electrical resistance as a measurement of wood moisture content. Electricity flows more easily and quickly through the wood as the moisture content increases. The temperature of the wood can sometimes affect readings, so many pin-type meters have temperature correction scales.

Wood moisture meters are about as accurate as you’re going to get unless you choose the “gold standard” of wood moisture measurement, which is the “oven-dry test.” This test weighs the wood wet and dry to compare and mathematically determine the moisture content. If you don’t have the time or inclination to bake your wood in an oven, you’ll want to choose a pin or pinless wood moisture meter that has been proven to provide results as close to the oven-dry test as possible.

A pinless wood moisture meter uses a flat sensor pad to send an electromagnetic signal into the wood and translate the electrical resistance of the wood into %MC (moisture content). So, the measurement occurs as a wave that sinks into the wood. Pin-type meters, on the other hand, use sharp pin electrodes that are pushed deep into the wood. The two electrodes send an electrical current to each other and the electrical resistance of the wood between the two pins is translated into %MC. Pinless wood moisture meters that use a flat sensor surface work best when the wood measuring surface is smooth. Pin-type meters are an advantage when measuring MC in wood that has an uneven or bumpy surface.

Undoubtedly, there will come a time when an enterprising start-up produces a device that reads wood moisture content as well as surface and airborne mold levels, but the reality is that you are more likely to find products that choose to develop either wood moisture measurement or mold detection to perfection. Unless there is an amazing new product out there that combines the two, it’s probably best to find the best device in each category.

Pin-type meters and pinless wood moisture meters can read moisture content inside of drywall if they feature a calibrating mechanism or setting that adjusts the meter to the density of drywall. In the same way that pinless wood moisture meters must be calibrated or adjusted to measure different wood species with varying densities, they are also adjusted to account for the unique density of drywall.