![Precigrader: Acoustic MSR System](https://d27wgn5g4t3wja.cloudfront.net/img/6b8e6c2a-1422-08df-aa44-0d4f152bc0ae/332050.png)
Precigrader: Acoustic MSR System
Precigrader is an acoustic on-line strength grading system. The system is installed in more than 150 mills. It is used to determine common commercial grades in North America, including 1650 and 2100. A spring-loaded impact mechanism strikes the lumber as it passes. The resulting vibration is captured by microphones to determine the appropriate MSR grade.