The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 04, 2001
Filed:
Aug. 25, 1998
Neil B. Bromberg, Milwaukee, WI (US);
Hui David He, Waukesha, WI (US);
Mary Sue Kulpins, New Berlin, WI (US);
General Electric Company, Schenectady, NY (US);
Abstract
Methods and apparatus for detecting cell to cell variation to ensure that the maximum allowable channel to channel variation is not exceeded are described. In one embodiment, an algorithm is periodically executed to measure the relative gains in the channels. The gains are measured, for example, by recording the signal from an air scan and normalizing to a common reference. Part of the normalization process includes accounting for the non uniformity of the x-ray beam, for example, the heel effect. It is assumed that the x-ray flux profile in z is slowly changing in the x-direction and is obtained by low pass filtering in x. The normalized values are then compared to a predetermined specification. If any particular cell is not within the specification parameters, then the module in which such cell resides may be replaced. In addition to measuring gain variation and comparing it to a specification, a trending analysis also may be performed. The trending algorithm predicts the time at which the detector will fail the specification so that replacement of the detector may take place before failure occurs.