Abstract: The measuring system for monitoring buildings, terrain sections or the like consists of a beam waveguide bending sensor which has a multimode beam waveguide (GI) and is disposed in the shape of a loop. Several arc-shaped sensor sections (S) are disposed between support plates, which are movable in respect to the sensor sections and and fixedly connected with areas of the building or terrain sections. A light source and light receiver with an evaluation device for light subduing values are connected to the beam waveguide bending sensor. The beam waveguide bending sensor is disposed in the form of several loops. The beam waveguide bending sensor consists of gradient-index-multimode beam waveguide sections (GI) and step-index-multimode beam waveguide sections (SI) connected therewith, wherein the sensor sections (S) are formed by the gradient-index-multimode beam waveguide (GI).

Abstract: A light waveguide sensor for small pulling or pressing forces comprises a primarily coated light waveguide, a coil wound on the light waveguide and composed of an element having a diameter which is smaller than a diameter of the primarily coated light waveguide, a casing surrounding the primarily coated light waveguide and the coil and composed of a fiber reinforced synthetic plastic material with longitudinally extending, pulling resistant fibers embedded in a synthetic plastic matrix, the coil being composed of a plurality of coils arranged in cross-lay relative to one another on the light waveguide and each having a pitch length greater than 2.2 times the diameter of the primarily coated light waveguide.

Abstract: A measuring device with a light wave conductor-bending sensor for monitoring bridge structures comprises a light emitter and a light receiver, a multi-mode light wave conductor arranged to extend along a structural part and having two ends connected with the light emitter and the light receiver, respectively, an elongated plate having a lower side arranged to be placed on and connected with the structural part and also having an upper side provided with a longitudinal groove, two sliding rails arranged in the longitudinal groove and having outer ends fixed to the plate and inner ends spaced from one another to form an intermediate space and movable relative to the plate. The light wave conductor is fixed with one of the sliding rails, then extends through the intermediate space and forms a freely movable curve, and then exztends along and is fixed to the other of the movable rails.