Patent ID: 7643608

Claim:
A method for checking for leakage from tubular batteries, comprising: feeding tubular batteries with respective axial centers thereof aligned in parallel to each other to pass through a leakage check section placed opposite to a detection window of a leakage check mechanism; irradiating a sealed end face of the tubular battery in the leakage check section with an X-ray through the detection window and allowing a fluorescent X-ray coming out of the sealed end face to enter a fluorescent X-ray detector through the detection window; and analyzing whether a fluorescent X-ray associated with an electrolyte component is contained in the incident fluorescent X-ray to thereby determine whether leakage occurs from the tubular battery, wherein the detection window is defined in such a shape that a length thereof in a direction of feed of the tubular batteries is less than a spacing between the tubular batteries being fed, and a length thereof in an orientation orthogonal to the direction of feed is slightly larger than an outer size of the cross-sectional shape of the tubular batteries in an orientation orthogonal to their axial center.