Method for slot inspection

A method for inspecting a workpiece (100), the workpiece (100) comprising a slot (110) with a proximal end (P) and a distal end (D), the method comprising:

• receiving a dimensional model (210) of at least part of the workpiece comprising at least part of the slot (110);
• and
• determining a burnish region (220) of the slot (110) that is a continuous region having an essentially constant profile from the dimensional model (210)
• wherein determining the burnish region (220) comprises:
• defining in the dimensional model (210) an entry region (212), and an inner mantle (214) from the dimensional model (210), wherein the entry region (212) is located at the proximal end (P) of the slot;
• and the inner mantle (214) is distal to the entry region (212), wherein the inner mantle (214) is used to identify the burnish region (220),
• subdividing the inner mantle (214) into a plurality of slices (216) along the slot axis (114) each of a predetermined height, wherein for at least two slices, preferably all slices (216a to 216e) a plane geometric shape (218a to 218e), preferably a circle, is generated and fitted to each of the respective slices (216a to 216e), preferably wherein the fitted plane geometric shapes (FPGSs) (218a to 218e) are each disposed essentially perpendicular to the slot axis (114), and preferably wherein the fitted plane geometric shapes (FPGSs) (218a to 218e) are each fitted inside a peripheral boundary of the respective slices (216a to 216e).