Abstract: Disclosed is a method for determining physical properties of a test sample using a spectrometric detector with at least three channels, consisting of: performing measurements in each of the channels on the test sample, calculating variables, each formed from a combination of measurements of different channels, and applying a weighting and bias matrix to the variables, enabling the investigated physical properties of the test sample to be determined.

Abstract: Disclosed is a method for determining physical properties of a test sample using a spectrometric detector with at least three channels, consisting of: performing measurements in each of the channels on the test sample, calculating variables, each formed from a combination of measurements of different channels, and applying a weighting and bias matrix to the variables, enabling the investigated physical properties of the test sample to be determined.

Abstract: The present invention concerns a method and implementing equipment for detecting at least one object containing a specified material and hidden from view. The method comprising stages of object irradiation by a collimated x-ray beam (21) with an energy range containing a photo-ionization threshold, of detection of the beam having passed through said object (24), is characterized in that furthermore a continuous function representing the attenuation or transmission of the x-rays expressed in terms of energy is determined and a search is made near the energy corresponding to said photo-ionization threshold along the curve representing said continuous function of attenuation or transmission of an inflection point characteristic of the presence of said material. Illustratively this invention is applicable to airport luggage inspection.

Abstract: The 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 (F.sub.p1, F.sub.p2, F.sub.p3, F.sub.p4) 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.

Abstract: The object's transmission function is expressed as a finite power expansion of a reference-material reference thickness, each expansion power being equal to a ratio of a reference-material thickness to the reference thickness; the expansion coefficients are determined from the measurements of the intensities transmitted by the selected various thicknesses, including zero thickness, of the reference material exposed to a test beam evincing consecutively several energy spectra and from the measurements of the intensity transmitted by the object exposed to this same variable-spectrum test beam; the attenuation function is derived from the determination of the transmission function.