Abstract: Axial fan compact bearing viscous pump having two spaced apart bearing housings and a bearing supported within each bearing housing. A shaft is supported within each bearing housing. The shaft has two oil disks, each bearing having an oil disk proximate thereto. The portion of each bearing housing fitting about a respective one of the oil disks forms a viscous pump housing. The viscous pump housing has an oil inlet and an oil outlet. The oil outlet is spaced from the oil inlet. On an inner periphery of the viscous pump housing, an oil channel in an inner periphery facing an outer periphery of the one of the oil disks extends only partway around the viscous pump housing inner periphery. The oil channel extends from the oil inlet in the direction of rotation of the shaft to a point beyond the oil outlet.

Abstract: Calibration of a light scanner, particularly for measuring particles and surface finishes in the inspection of substrates uses a strongly scattering reference medium. A focused laser beam is directed onto the reference medium which is disposed outside the focal plane of the beam. Scattered light from the medium is thus defocused with respect to a photodetector that collects the scattered light. An amplifier connected to the photodetector measures the intensity of the scattered light. By the use of filters in the path of the light calibration of the optico-electronic system of the scanner is achieved.