GEO-TOPOGRAPHIC MARK

摘要

The invention relates to a geo-topographic mark used in cadastre works, topographic works or for signalling some vertical or horizontal displacements of some hydrotechnic constructions (19). According to the invention, the mark comprises a metal cylinder provided at the lower side with a conic tip, and at the upper side with a parallelipiped (3) having on a lateral side a metal mirror (14), the said mirror being located so as to receive and reflect a laser ray emitted by a specialized diode (15) mounted in a support (16) fastened in a stable area, the reflected ray being received by a photoelectric sensor (17) connected to a signalling device which emitts a sonorous warning signal if the geo-topographic mark undergoes vertical or horizontal displacements.