Patent ID: 7561663

Claim:
An X-ray detection device for foreign matter ( 1 , 40 ) which irradiates an examination subject article being conveyed in a conveyance path with X-rays at a predetermined detection position and which determines, on the basis of the transmission amount of X-rays that have penetrated through the examination subject article, whether or not foreign matter is mixed in, characterized in that the X-ray detection device comprises: a test-piece table ( 17 , 49 ) which, being outside the conveyance path, holds a test piece ( 21 ) for checking sensitivity of detecting the mixed-in foreign matter and which is movably installed so that it can pass the detection position along a moving direction of the examination subject article moving in the conveyance path; and means ( 19 , 43 ) for moving the test-piece table along the moving direction at substantially the same speed as a moving speed of the examination subject article.