Method and Apparatus for Detecting and Characterizing Splits in Logs

Forest Service

Traditional visual and optical methods of inspecting defects and other features are defeated by superficial defects in the wooden members such as dirt, bark, stain or other markings on the outside of the log. More importantly, internal defects such as splits are generally not visible. This invention uses ultrasonic techniques to detect splits in logs or other wooden members.  Splits create an acoustic discontinuity that may be detected by ultrasonic signals transmitted through the wooden member across the grain and at a number of different angles.  Even after the splits have closed and are no longer visible, they create an acoustic discontinuity that may be detected.  Detection of the splits may be used to control the operation of a saw to change cut locations or modify the sawing technique.  The present invention is robust against the harsh environment of a typical lumber operation and is safer, less costly and more compact than other similar instruments.

Patent Number 6,092,418, which issued on July 25, 2000.