| 摘要 |
1. Method for the industrial quantitative tomodensitometry of a work piece (1) by means of an electromagnetic radiation beam (2), in which a plurality of sections (sk) of said work piece (1) are observed successively by means of said beam (2) and the attenuation undergone by this latter is measured, according to a process comprising : A) each section (sk) observed is subdivided fictitiously into a plurality of individual contiguous zones (aij) having a rectangular or square shape and distributed into lines and columns parallel to two rectangular directions (OX, OY), with each of which zones is associated an unknown (xij) representing the coefficient of attenuation per unit of length of said zone with respect to said beam (2) ; B) a relative step by step movement is applied between each of said sections (sk) and said electromagnetic radiation beam (2), so that the latter and said zones (aij) of the corresponding section (sk) take up a plurality of relative positions, the number of said relative positions being greater than that of said individual zones ; C) then, for each of these relative positions : a) the length (eij) of the path of said beam (2) in each of said zones (aij) through which it passes is calculated ; b) an equation term S is formed, constituted by the sum of the different products (xij.eij) of the coefficient of attenuation per unit of length (xij) multiplied by said length (eij) of the path of the beam, for each of the zones passed through by said beam ; c) the intensity I of the beam is measured after passing through the corresponding zones of the section and the expression in In Io/I is formed, Io being the intensity of said beam before passing through said zones ; d) the following equation is formed : In Io/I = S, D) after which, for the whole of said relative positions between the beam (2) and said zones (aij) of the section (sk), the different equations In Io/I = S are gathered together so as to form them into a system of equations which is resolved for determining the value of the coefficient of attenuation per unit of length (xij) of each zone (aij) of the section, characterized in that said relative movement between each of said sections (sk) and said beam (2) is a translation movement, the direction of which is both orthogonal to said beam and parallel to one side of said zone (aij).
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