Most Lumber Used in Building Construction Is Visually Graded

Essay

Most lumber used in building construction is visually graded. The traditional visual grading was done by trained graders, who would examine each lumber member for the straightness of grain and the number and size of defects (knots, shakes, and splits)and mark the appropriate grade on the member based on visual assessment. Recently, this procedure has been replaced by an alternative procedure. What is this new procedure called, and what is the fundamental difference between the new and the traditional procedure?