Patent ID: 8031346

Claim:
A method for evaluating variations in thickness of a coating formed along a contour on a turbine blade, the blade being of a type having a first region extending over a range of 360 degrees about the blade and a second region including an exposed reference surface, the first region including a first surface over which the coating is formed and a second surface formed by the coating, the method comprising: prior to forming the coating over the blade and with the first surface visibly exposed, forming a first set of optical patterns thereover; performing non-scanning optical imaging to acquire a first set of point cloud data based on the first set of optical patterns and representative of the first surface along the first region relative to an exposed reference point along the reference surface, the first set of data including coordinates characterizing spatial attributes of the first exposed surface; forming the coating over the first region to cover the first surface and provide a second exposed surface while leaving the reference point exposed; after forming the coating over the first region, forming a second set of optical patterns thereover; performing non-scanning optical imaging to acquire a second set of point cloud data based on the second set of optical patterns and representative of the second surface along the first region relative to the exposed reference point, the second set of data including coordinates characterizing spatial attributes of the second exposed surface; and calculating a set of values indicative of thickness variations in the coating based on differences between data values in the first and second sets of point cloud data.