METHOD OF CONTACTLESS THICKNESS MEASUREMENT Russian patent published in 1996 - IPC

FIELD: measurement technology. SUBSTANCE: invention can be used in light industry for automation of process of hide sorting. Reference probing radiation beams and additional probing beam oriented in parallel to reference beams and set at specified distance from them arranged on one straight line are directed on to controlled object from two opposite sides. Radiation beams are reflected from controlled object and form light spots in image planes of optical systems mounted properly on two opposite sides of controlled object. Coordinates of formed light spots are measured, by measurement results lengths of sections of reference and additional beams from projections on them of centers of optical systems to controlled object are determined by triangulation method. Thickness h of controlled object is calculated by formula , where l₀ is projection of distance between centers of optical systems on to line of reference beams; l₁, l₂ are lengths of sections of reference beams from projections on them of centers of corresponding optical systems to controlled object; l₃ is length of section of additional beam from projection on to it of center of corresponding optical system to controlled object; d is distance between directions of additional l₃ and corresponding reference l₁ beams (specified in advance). When checking rolled or sheet materials one positions additional beam so that plane crossing it and reference beams is oriented in parallel to direction of movement of material. Method demonstrates expanded technological capabilities and makes it possible to measure thickness of rigid hides under automatic mode. EFFECT: increased precision of measurements thanks to exclusion of errors caused by uncontrolled inclination of object. 2 cl, 2 dwg