GradeScan uses data from up to six different sensors to find
knot heads on all four sides of the board.
The image below is a portion of a 2 x 10 White
Fir board. The purple boxes show the knot heads
found by GradeScan on the top surface.
Below is a magnified section of the same board. The
small magenta box in the middle of the face toward
the left edge is actually a pitch pocket. GradeScan
was not fooled by the pocket's knot-like color.
Even the small pin knot on the very edge of the board
is boxed correctly.
GradeScan's optimizer gathers the data from all sides into a three-dimensional object and calculates the exact knot displacement.