The penetrating moisture meter is used mainly to detect moisture levels in drywall and baseboards. It also gives a reading in wood floors and furniture, but these situations often call for a different approach of detection.

Two small metal prongs are inserted into the material being tested. A small electrical current is sent from one prong to the other. Because water is a better conductor of electricity than most building materials, the meter picks up a greater charge when the tested object is wet.

A digital display easily tells the user within 0.1% how much water is in the material being tested.