JPS56107111A - Measuring device for displacement in construction of structure - Google Patents

Abstract

PURPOSE:To measure displacement in construction of a structure easily and accurately by providing two slits crossing each other in a photointercepting film which is located between an oscillator oscillating a beam along the direction of construction of the structure and a beam receiver and moves in the direction perpendicular to the beam. CONSTITUTION:On the foundation part 2 of the structure 1 is installed a laser-beam emitter 3, from which the beam is emitted intermittently upward vertically. The frame of the structure 1 is fitted with a laser-beam receiver 5 monolithically. With a start signal of a microcomputer 20, the photointercepting film 8 is rolled up by a roll-up roll 7 positioned in the right and carried toward the right, and when the slit 15 comes near to the left end of a Fresnel beam-condensing plate 9, a photointerrupter 12 starts operation. When the slit 15 crosses the beam 4, the latter enters a case 6 and the constituent thereof in the direction X is measured through the intermediary of a diffusion plate 10, a photosensor 11 and an amplifier 19. Next, when the slit 16 cutting the slit 15 at an angle of 45 deg. comes to the position of the beam 4, the constitutent in the direction Y is measured, and thus the displacement in construction can be measured easily and accurately.