Electric moisture meters measure moisture content of wood in terms of its electric resistance or dielectric properties, which vary reasonably consistently with moisture contents under about 30 percent. Moisture meters may be either handheld or stationary. Readings of these meters are affected by such factors as species, temperature, chemical treatments, moisture distribution, operator skill, and others. Information is given here either to correct for these factors or to minimize errors that they may cause. The two major classes of these meters are the resistance type and the dielectric type, each with its particular advantages. A list of suppliers of these instruments is included.