Abstract: A device for indicating the percentage of ultraviolet radiation which reaches the earth's surface for a given position of the Sun's altitude. The device consists of a planar member having a gnomon-like member affixed within its center. The gnomon-like member marks the center of nine (9) spaced concentric rings inscribed on a top surface of the planar member. The innermost circle is labeled 90%, the second 80% and so on to an outer edge. The radius for the circumference of each ring is calculated by a mathematical formula which correlates the altitude of the sun with a percentage amount of UV-B that reaches the surface of the earth.

Abstract: The relative position of a plurality of holes through a surface of a member, the holes having been generated by high energy means, such as a laser, which vaporizes material of the member to produce a light flash, is inspected and controlled as the holes are being generated using a light sensing means which is responsive to the light flash and which observes the relative positions of the holes being produced. The light sensing means signals a hole pattern comparison means which compares the actual hole pattern with a preselected hole pattern. Adjustment can then be made to reposition the high energy beam if required to correct undesirable error in the actual hole pattern during generation of the holes.