Optical device for measuring small pressure differences by means of light intensity changes

摘要

The invention proceeds from the finding that the deflection of a mirror-coated membrane surface can be used for the purpose of deflecting a light beam, of predetermined intensity, passed via appropriate optical means, in accordance with the measured pressure, so that the intensity of the light to be reemitted is variable as a function of the measured pressure. A measurement body is provided, in which an at least partially mirror-coated membrane is tensioned in such a manner that it is positioned with its mirror-coated surface in its rest position surface-parallel at a spacing which is slightly greater than an expected maximum deflection of the membrane, to an end surface of a graduated lens, and in which the graduated lens is positioned so that this end surface is disposed eccentrically opposite the membrane, so that as a result of flexings of the membrane which are caused by pressure effects the beam path of a light passed via the other end surface by means of optical waveguides as entrance fibre is displaceable within the graduated lens in consequence of the altered angle of incidence at the mirror-coated surface, so that the light intensity in an exit fibre is variable. IMAGE