METHOD AND DEVICE FOR IDENTIFYING DESIGNATED MATERIALS IN THE COMPOSITION OF AN OBJECT

PCT No. PCT/FR94/00580 Sec. 371 Date Jul. 12, 1996 Sec. 102(e) Date Jul. 12, 1996 PCT Filed May 16, 1994 PCT Pub. No. WO94/28442 PCT Pub. Date Dec. 8, 1994The method comprises the following stages: first the attenuation function of at least three reference materials are determined across a wide x-ray spectrum and projection functions (Fp1, Fp2, Fp3, Fp4) forming a base are derived therefrom, then the attenuation function in said x-ray spectrum of at least one target material is determined and the attenuation function of each target material is projected onto said base; further, for each point of the object (1), the attenuation function of the object (1) is determined in said x-ray spectrum and projected onto said base, and the projections so obtained are compared with the projection from each target material and from this comparison an inference is made whether at least one target material enters the constitution of the object (1) at the point of inspection. Application: luggage inspection and control.