Abstract: A device for illuminating components of transparent material by dot-scanning so that the components may be tested for surface irregularities and occlusions which comprises a component rotatably mounted so that the component may be rotated on its axis at a predetermined speed, a light source for generating a parallel light beam for illuminating the component, and a mechanism for periodically linearly deflecting the light beam at a frequency greater than the predetermined rotational speed of the component. The periodically linearly deflecting mechanism is disposed in the path of the light beam between the parallel light beam generating source and the component. The device also includes a focusing lens for focusing the light beam in a testing plane, where the focusing lens is disposed between the periodically linearly deflecting mechanism and the component at a location whereby the focal point of the focusing lens is at the edge of the periodically linearly deflecting mechanism.

Abstract: A device for testing components of transparent material for surface irregularities and occlusions which comprises a mechanism for rotatably mounting the component so that the component may be rotated on its axis; a mechanism for generating a light ray which moves linearly so that the light ray can dot-scan the component along a diameter of the component; at least one signal generating device disposed at a predetermined angle to the direction of impingement of the light ray for detecting surface irregularities and occlusions of the component and then generating a signal representative of the irregularity or occlusion; and a signal evaluation device for evaluating the signals produced in the signal generating device.

Abstract: The diameter of a wheel or wheels, such as railroad wheels, is measured while the wheel rolls through a measuring station or while a measuring station is moved past a wheel. Electromagnetic beams, such as light or laser beams, provide respective barriers or sensors. The spacing between the beams is fixed and the time needed to traverse the spacing is measured. The spacing has a definite relationship to the wheel diameter. A computer calculates the diameter based on the measured time and on the given wheel diameter related spacing. Even where only a portion of a wheel is available for sensing or scanning the present method may be used.