A method of comparing surface profiles of an object, the object being rotatable on an axis, such that the object has a longitudinal dimension and an axial dimension. The object is incrementally scanned with a laser scan micrometer, first in a pre-test scan procedure and then in a post-test scan procedure. The two scan procedures are performed in the same manner, by using the laser scan micrometer to scan the object in a longitudinal direction, rotating the object, re-scanning the object, measuring the scan length thereby obtaining a longitudinal height value, and repeating the preceding steps for a number of incremental rotations thereby obtaining one longitudinal height profile. This process is repeated by incrementally moving the object in an axial direction and acquiring additional longitudinal height profiles, thereby acquiring a set of longitudinal height profiles. The pre-test and post-test sets of profiles are then aligned and compared.
Eric Liu; Sean C. Mitchem; Kerry J. McCubbin