US 5,585,603 A · Method and system for weighing objects using X-rays

Abstract

A method and system for weighing an object as it is carried on a conveyor past an x-ray source. X-rays from the x-ray source pass through the object, are attenuated in proportion to the mass of the object through which they pass, and impinge upon an x-ray detector array. X-ray detector array includes a layer of scintillating material that produces light in response to the intensity of the x-rays and a plurality of photodiodes to detect the light. The intensity of the x-rays received at the x-ray detector array is indicated by signals produced by the photodiodes, which are periodically scanned by a processor. The photodiode signals are each converted to a value representing the average areal density for a volume element extending above the photodiode into the object. Using the average areal density for each volume element and the size of each volume element, the processor determines the mass of the volume element. The entire object is advanced, and the mass of the volume elements in the object are generated and stored. The total mass of an object is determined by summing the masses of the volume elements, and a mass map of an object is generated that represents the location and mass of all of the volume elements in the object.

Claims30

Dependent claims

A method of weighing an object transported on a conveyance means, the method comprising the steps of:

(a) positioning an object to be weighed adjacent an x-ray source that generates x-rays;
(b) exposing a portion of the object to the x-rays;
(c) dividing the portion of the object exposed to x-rays into an array of volume elements;
(d) detecting an intensity of the x-rays after they have passed through the object;
(e) calculating a mass of each volume element of the object based on the intensity of the x-rays that have passed through the object;
and
(f) summing the mass of each volume element to determine a mass of the portion of the object exposed to x-rays.

4 more elements

A weighing system for weighing objects transported on a conveyance means, the weighing system comprising:

(a) an x-ray source;
(b) conveyance means for carrying an object to be weighed past the x-ray source;
(c) a sensor for generating a sensor signal indicative of a position of the object;
(d) a plurality of x-ray detectors positioned to receive x-rays emitted by the x-ray source that pass through the object to be weighed, each of the plurality of x-ray detectors generating a signal corresponding to an intensity of the x-rays impinging upon the x-ray detector;
and
(e) a processor comprising:
(1) means for receiving the sensor signal and the signals generated by the plurality of x-ray detectors;
(2) means for determining the portion of the object exposed to the x-rays from the received sensor signal;
(3) means for partitioning the portion of the object exposed to the x-rays into a plurality of volume elements, each of the plurality of volume elements associated with one of the plurality of x-ray detectors;
and
(4) means for calculating the mass of each of the plurality of volume elements based on the associated signal from one of the plurality of x-ray detectors.

8 more elements

Dependencies are inferred from the claim text.

Method and system for weighing objects using X-rays

Life of this patent

Method and system for weighing objects using X-rays

Life of this patent

Abstract

Claims30