Apparatus and method for non-destructive inspection of material in containers
An apparatus and method for non-destructive inspection of materials housed in containers ( 16 ) involves orienting an X-ray beam emitter ( 10 ) and detector ( 14 ) to direct and detect an X-ray beam ( 12 ) at an angle ( 34 ) lying in a range of from 8° to 20° to a conveying direction ( 22 ) of a conveyor ( 18 ) along which the materials are conveyed. The beam angle to the conveying direction works best between 8° and 12°, with an optimum being at approximately 10°. This arrangement de-emphasizes the leading and trailing edges of the containers while not substantially changing the image from that of a perpendicular beam, so that the detector images are still relatively easy to analyze. Thus, a one-detector system is adequate in many cases.
1. Apparatus for non-destructively inspecting materials housed in containers, said apparatus comprising:
a conveyor for conveying said containers along a conveying path in a conveying direction;
an X-ray beam emitter mounted at a first position adjacent said conveying path for emitting an X-ray beam passing through said containers as they are conveyed along said conveying path;
a detector mounted at a second position adjacent said conveying path on a side of said conveying path opposite that of said first position for receiving a transilluminated portion of the X-ray beam that has passed through said containers and generating therefrom an image signal representative of the transilluminated portion; and
wherein said X-ray beam emitter is oriented to direct the X-ray beam at an angle to a plane perpendicular to the conveying direction, said angle lying in an angle range of 8° to 20° inclusive and wherein said detector is properly positioned and oriented to receive the angled X-ray beam.
2. Apparatus as in claim 1 , wherein said angle range is from 8° to 12°, inclusive.
3. Apparatus as in claim 2 , wherein said angle range is from 9° to 11°, inclusive.
4. Apparatus as in claim 3 , wherein said angle is approximately 10°.
5. Apparatus as in claim 1 , wherein said detector's position can be selectively adjusted toward and away from said conveying path as well as along a line parallel to said conveying path.
6. Apparatus as in claim 1 , wherein there is only one beam emitter and one detector for the conveying path.
7. A method for the non-destructive inspection of material housed in containers, said method comprising:
conveying the containers along a conveying path;
passing an X-ray beam through said containers as they are conveyed along said conveying path;
receiving a transilluminated portion of the X-ray beam passed through said containers; and
generating a signal representative of the transilluminated portion and therefore of an image representative of said material;
wherein said X-ray beam is directed at an angle to a plane perpendicular to the conveying path, said angle lying in an angle range of 8° to 20° inclusive.
8. A method as in claim 7 , wherein said angle is in a range of 8° to 12°, inclusive.
9. A method as in claim 8 , wherein said angle is in a range of 9° to 11°, inclusive.
10. A method as in claim 9 , wherein said angle is approximately 10°.
11. A method as in claim 7 , wherein there is only one X-ray beam and one detector along the conveying path for carrying out said method.