Method and device for measuring the flatness of a metal product

摘要

A method measures the flatness of a metal product and an associated device. The method applies to a metal product, in the form of either a strip or a plate from a metallurgical processing line. The product to be measured being, by default, free of external traction. The method contains the following steps: a) illuminating a portion of a face of the product under uniform intensity; b) capturing an image of a light line of the illuminated portion; c) relatively moving the illuminated portion and the light line in a defined direction in relation to the product; d) repeating steps a), b), c); and e) collecting the images of lines in a two-dimensional distribution of intensities and selecting a strand direction of the product in which, if at least one wave of intensities is detected, a local amplitude variation of the wave delivers a local strand flatness defect value.

主权项

1. A method for measuring a flatness of a metal product selected from the group consisting of strips and plates from a metallurgical processing line, which comprises the following steps:
a) illuminating a portion of at least one face of the metal product under uniform intensity; b) capturing an image of a light line of an illuminated portion of the metal product; c) relatively moving the illuminated portion and the light line in a defined direction in relation to the metal product; d) repeating steps a), b), and c); and e) collecting images of lines in a two-dimensional distribution of intensities and selecting a line direction of the metal product in which, if at least one wave of light intensities is detected, a local amplitude variation of the at least one wave defines a local strand flatness defect value, wherein the wave of light intensities detected results from a variation in orientation of a hollow or bump in each strand inducing a variation in an amplitude of intensities measured, which are compared to an evaluation of a length of each of the strands under its own intrinsic traction and having its own flatness value.