A method of measuring and storing a center of rotation of a nozzle in a
pick and place machine is provided. The method includes coupling an
artifact to the nozzle. A substantially collimated laser beam is directed
at the artifact, which is rotated while the collimated laser beam is
energized. Edges of a shadow cast by the rotating artifact are detected
and used to calculate error of a coordinate of the center of rotation of
the nozzle. A coordinate of the center of rotation of the nozzle is
calculated based upon a previous coordinate of the center of rotation and
the error. The calculated coordinate of the center of rotation is stored
for subsequent measurements.