Southern pine dimension lumber is produced by a large number of mills in Georgia, in great quantities. All lumber used where it must meet building codes has to be grademarked. For grademarking, moisture-content limits for the specified grade must be met. Various moisture meter types and brands are used to determine wood moisture content, but pin-type resistance meters are used as the standard by grading agencies responsible for overseeing mill graders. Most common meters produce acceptably accurate results within the range of seven to 25% wood moisture content.
Pin meters have been used for years, and are made by many different companies. Newest meters are very sophisticated, with automatic internal calibration and with many correction factors and statistical functions built in. However, using resistance meters still requires driving pins into lumber to obtain indications of moisture content. This process usually requires properly insulated pins, is relatively slow, must be done carefully for best results and sometimes results in broken pins which can cause planer problems. However, long experience has given pin meters a reputation for reliability and useful accuracy.
Other moisture meters have been developed which use electromagnetic energy to determine moisture content, and do not physically penetrate into wood. This usually means readings can be made faster and much easier than with pin meters. However, these meters do not have the history of success with Southern pine that pin meters have. They are acknowledged to be highly influenced by density of the lumber being examined too.