Most meters can be affected by standing water, or visible water on the board. You should always wipe off as much excess water as possible. Once the standing water is removed, a pin-type moisture meter with non-insulated pins will register a highly exaggerated reading. Wagner Meters handheld moisture meters will read slightly higher than normal (probably less than 3 to 4%). If water is allowed to soak into the wood, it will naturally show a higher moisture content. If a piece of wood is quite rough, it will soak up the water quite readily and readings will be affected.