Computed tomography metrology

A method for comparing actual geometry to predetermined geometry of an object, the method comprising:

• three-dimensionally scanning the object using computed tomography (CT) to produce multiple slices of actual geometrical data of the object;
• processing said multiple slices of actual geometrical data into actual boundary data which defines internal and external actual boundaries of the object and features of the object;
• producing point cloud data from the actual boundary data;
• comparing the point cloud data to object geometry predetermined data wherein said comparing of the point cloud data to the predetermined data includes registrating the point cloud data to coordinates of the predetermined data and outputting an image comparing the point cloud data to the predetermined data wherein the image is an image of an interior feature of the object;
• said outputting includes producing an image representing the geometry of non-conformance between the point cloud data and the predetermined data and displaying the image on a color computer monitor by displaying a plurality of pixels representing the geometry of non-conformance between the point cloud data and the predetermined data of the interior feature of the object which is a core.

A method for comparing actual geometry to predetermined geometry of an object, the method comprising:

• three-dimensionally scanning the object using computed tomography (CT) to produce multiple slices of actual geometrical data of the object;
• processing said multiple slices of actual geometrical data into actual boundary data which defines internal and external actual boundaries of the object and features of the object;
• producing point cloud data from the actual boundary data;
• comparing the point cloud data to object geometry predetermined data wherein said comparing of the point cloud data to the predetermined data includes registrating the point cloud data to coordinates of the predetermined data;
• and
• comparing an actual geometric definition to a predetermined geometric definition of a feature of the object by generating a curve fitted geometry of the point cloud data representing the feature, calculating the actual geometric definition from the curve fitted geometry, and comparing the actual geometric definition to the predetermined geometric definition wherein the object is a cooled turbine airfoil having at least one plurality of turbine cooling holes extending from an internal cavity through an outer wall of the airfoil.