Apparatus for measuring coating film swelling width of coated metal sheet and method for measuring coating film swelling width of coated metal sheet

摘要

To provide a coating-film blistering width measuring apparatus for a coated metal plate that can measure the coating-film blistering width of a coated metal plate.SOLUTION: A coating-film blistering width measuring apparatus for measuring the coating-film blistering width of a coated metal plate that is scratched on its surface and is corroded under a corrosive environment comprises: a sample table; an imaging means; a lighting means that can illuminate the surface of the coated metal plate at least from two directions; and a calculation means for calculating the coating-film blistering width of the coated metal plate. In the coating-film blistering width measuring apparatus for a coated metal plate, the above calculation means: extracts the scratch position on the surface of the coated metal based on a first image in which the surface of the coated metal plate is imaged in a state of illuminating the surface at least from one of the two directions by the lighting means and on a second image in which the surface is imaged in a state of illuminating the surface from the other direction than the direction above; extracts the coating-film blistering position on the surface based on the first and second images and others; and calculates the coating-film blistering width of the coated metal plate based on the extracted scratch position and the extracted coating-film blistering position.SELECTED DRAWING: Figure 1