Abstract: The invention relates to a device for recognizing the impact site (29, 37) of a charge carrier beam on a target. This device has two position-sensitive detectors (22, 23) above the target which have a given distance from each other and from the target and on which via imaging systems (24, 25) the impact site (29, 37) of the charge carrier beam is imaged by means of X-rays. The output signals of these detectors (22, 23) are placed on a special evaluation device which determines all three spatial coordinates of the impact site (29, 37) of the charge carrier beam.

Abstract: Process for measuring the optical properties of thin layers while they are being built up in vacuum coating installations. For this purpose, at least one test object is passed through a stationary measuring light beam and the transmission behavior of the test object is evaluated by measurement. A reference point for the measurements is fixed in each case by reference measurements at intervals of time. In addition, at least one opaque measurement zone and at least one measuring zone, which does not attenuate the measuring light beam, are disposed in path of motion of the test object. The ratio of the measured value of the test object, decreased by the measured value of the opaque measuring zone, to the measured value of the nonattenuating measuring zone, decreased by the measured value of the opaque measuring zone, is formed by an arithmetic logic unit.