Abstract: The invention relates to a monitoring system for a conveying device for flat articles, especially wafers, which conveying device is provided with a carriage (28) that is movable along a predetermined path next to a flat article (10) that is located at a predetermined removal location, the carriage having a receiving device for the accommodation of the flat article (10), which monitoring system contains a light source (50) having a light-exit window and a light receiver (52) having a light-admission window, whereby the light-exit window and the light-admission window are positioned in such a way that a light beam (60) directed form the light-exit window to the light-admission window is partially covered by the carriage (28) during its movement through the light beam, and an evaluation unit that is connected to the light receiver and that compares a target signal derived from its movement of the carriage along a target path with an actual signal derived from an actual movement of the carriage, and indicates a d

Abstract: The invention relates to a monitoring system for a conveying device for flat articles, especially wafers, which conveying device is provided with a carriage (28) that is movable along a predetermined path next to a flat article (10) that is located at a predetermined removal location, the carriage having a receiving device for the accommodation of the flat article (10), which monitoring system contains a light source (50) having a light-exit window and a light receiver (52) having a light-admission window, whereby the light-exit window and the light-admission window are positioned in such a way that a light beam (60) directed form the light-exit window to the light-admission window is partially covered by the carriage (28) during its movement through the light beam, and an evaluation unit that is connected to the light receiver and that compares a target signal derived from its movement of the carriage along a target path with an actual signal derived from an actual movement of the carriage, and indicates a d

Abstract: In a method for determining the length of a light guide light of two different wavelengths or wavelength ranges is passed through a light guide whose length is to be measured. The ratio of incident light intensity to exit light intensity for each one of the wavelengths or wavelength ranges of the light passing through the light guide is determined. The length of the light guide is calculated based on wavelength-dependent attenuation coefficients of the light guide and the ratios of incident light intensity to exit light intensity for each one of the wavelengths or wavelength ranges of the light.

Abstract: An apparatus for measuring deformation of a body includes a transmitting optical fiber for connection to a light source and having a light exit face for radiating light, and at least first and second receiving optical fibers which have their light entrance faces adjacent to each other and which can each be connected to a respective input of an evaluation unit. The optical fibers are so arranged that upon deformation of the body there is a change in the difference between the amounts of light impinging on the light entrance faces of the receiving optical fibers.