Abstract: Electro-optical apparatus, system and method for measuring distance to a relatively moving surface, such as distance to a road surface from a vehicle frame of reference passing thereover. The apparatus includes a light transmitter for projecting a rectangular beam vertically downwardly onto the road surface. A rotating scanner includes a circumferential array of facets for sequentially receiving the image diffusely reflected from the road surface and reflecting such image through a rectangular reticle onto a photodetector. Reference beams are sequentially reflected by the road image-reflecting scanner facets onto a reference detector. Distance to the road surface is then determined as a function of the angle of incidence of the road image onto the scanner by comparing the time of incidence of the road image to the times of occurrence of the reference reflections on the reference detector.

Abstract: A semi-automatic penetration hardness tester for measuring hardness of a test specimen in a selected one of a number of hardness number scales. A digital display indicates penetrator displacement during application of a minor load in a first mode of operation and may be monitored by an operator to achieve a penetrator displacement within a preselected range corresponding to application of a minor load of desired magnitude. A control circuit senses manual initiation of a major load application and automatically scales the minor load penetrator reference position to a reference hardness number corresponding to and correlated with the selected hardness number scale. The control circuit also senses an operator error during the test procedure and automatically aborts the test.