The two main styles of wood moisture detectors (or moisture meters) are commonly known as “pin” meters and “pinless” meters.
Pin meters get their name from the fact that each moisture detector has two or more pins that must be pushed into the wood in order to take a reading. A small current travels from one pin through the wood into another pin. The drier the wood is, the less current is able to pass through. Pin meters read how much resistance there is to the current and correlate that resistance to the wood moisture content.
Pinless moisture meters do not have to pierce the wood to take a reading. Instead, they send out electrical waves to create an electromagnetic field (EMF) to a specified depth. The meters translate the impedance of this field to determine the moisture content of the wood.
Pros and Cons
The obvious drawback to a pin meter is the damage the pins cause to the surface of the wood. Some models are also rather difficult to use because cables are used to transmit the charge and can be easily tangled or twisted, and such movements may also affect readings. Most models have the digital display upside down when the pins are inserted.
On the plus side, the using insulated pins with pin meters means that they are rarely influenced by surface moisture.
Handheld pinless meters are typically simpler to operate, and as might be expected, do not damage the wood surface. But they can be much more susceptible to surface moisture – just wiping the surface with a damp cloth can make the readings skyrocket.
Both Wagner and Lignomat offer deeper reading depths, but Wagner’s IntelliSense™ Technology differentiates surface conditions for a much more highly accurate moisture reading from IN the wood, and offers a 3D average of the readings to avoid mis-reads from wet or dry pockets in the wood.
To learn more about handheld wood moisture meters with IntelliSense™ Technology, visit Wagner Meters’ site and view their line up.