Method and device for non-contact measurement of a distance to a surface or a distance between two surfaces

摘要

A measuring device for non-contact measurement of a distance to a surface (19) or a distance between two surfaces comprises a measuring light source (11) which generates polychromatic measuring light (12) and an optical measuring head (16) which detects the light emitted by the measuring light source (11 ) directed measuring light (12) on a measuring object (18) and thereof receives reflected measuring light (12 '). A spectrograph (20) with a dispersive optical element (22) and a detector (24) spectrally analyzes the reflected measuring light (12 '). A calibration light source (30) generates calibration light (32) of known and temperature-independent spectral composition. An evaluation device (28) derives from changes in a spectrum which is generated by the calibration light (32) on photosensitive cells (26) of the detector (24), correction values with which a predetermined assignment between the photosensitive cells (26) on the one hand and wavelengths or wavelengths derived from wavelengths, on the other hand.