WIZprobe

Nextec laser systems address this problem through “circumferential triangulation.” Like other designs, this involves emitting a laser beam that reflects off the measured surface and passes through a set of optics to a detector – in this case, a charge-coupled device, or CCD. The difference is that Nextec systems use toroidal optics. This shape enables collecting the reflected beam not just along a single return path, but from infinite angles simultaneously.

With more data to triangulate for a given portion of the part surface, the CCD can project a more complete and accurate depiction of the geometry.The donut-shaped optic enables us capture the beam’s entire cone of reflection from any given point on the part surface, and because we capture all the data from all 360 degrees, the output is a complete video image, just like you see on your camera screen.

However, the toroidal-shaped lens does nothing to account for changes in the energy of the reflected beam that can affect the integrity of measurement results. In addition to the varying angles that occur with blade edges and other minute, sculpted features, common culprits for this problem include a part’s surface finish and color. For example, a shiny surface will reflect most of the energy back to the light source, whereas an opaque, black surface will absorb it. In either case, the result is extraneous noise. This is a common limitation of not only laser systems, but also comparators, white-light scanners and other non-contact measurement processes.