METHOD FOR INSPECTING AN INTERNAL FLOATING ROOF IN A LIQUID-CONTAINING STORAGE TANK

摘要

Methods for remotely inspecting an internal floating roof and the seals associated with such internal floating roof project an illumination pattern from a series of substantially parallel laser beams onto the floating roof and/or the seal. Another laser beam projects at a predetermined angle offset from the series of laser beams. The illumination pattern and offset spot from the other laser are viewed through a camera. The length of a defect in the internal floating roof or seal or a gap between the seal and the tank wall is calculated as the length of a side of a right triangle based upon the predetermined angle and the predetermined distance between the lasers and the floating roof or seal.