METHOD FOR MEASURING DISPLACEMENT OF BRIDGE OF THE LIKE

摘要

PURPOSE:To certainly and sharply take the photograph of a measuring point even at night, by arranging a light source sight apparatus having a light source surrounded by a shield cylinder to the measuring point to take the photograph of said measuring point by a camera arranged at a measuring reference point. CONSTITUTION:A highly accurate photographing camera 1 constituted so as to be capable of setting horizontality or perpendicularity by mounting an air bubble tube and the like is arranged on a measuring reference point 3 through a tripod 2 while a light source sight apparatus 7 is arranged on the measuring point 5 of a bridge 4 through a tripod 6 to take a photograph by the camera 1. The light source sight apparatus 7 is constituted so that a target plate 10 is supported on a control stand 8 through a support arm 9 and light sources 11-14 are mounted on one side surface of the target plate 10 and blocked from light in a lateral direction by the shield cylinder 17 provided to the target plate 10 at a right angle so as not to allow lights from the light sources 11-14 to interfere each other. In taking a photograph, each of the light sources 11-14 of the light source sight apparatus 7 at the measuring point 4 nearest to the camera 1 are allowed to light by an operation apparatus 19 and the camera 1 is focused on the light source and the separate light source of the light source sight apparatus is subsequently allowed to light to successively take a photograph.