Abstract: An article for screening includes a top surface and a bottom surface. A forward wall, an aft wall and side walls each extend between the top surface and the bottom surface. A longitudinal recess extends at least partially across the top surface has a first lateral wall extending away from the top surface toward the bottom surface and meeting with a base wall at a predetermined angle therebetween for positioning of a liquid material relative to the first lateral wall and the base wall. The predetermined angle is for restricting data in a data range provided by a scanning operation of the liquid material to data provided within the predetermined angle between the first lateral wall and the base wall of the recess. The liquid material may be contained within a container positioned within the recess. Preferably, the article is an insert for a security screening tray.

Abstract: A method of determining at least one x-ray scanning system geometric property includes the steps of positioning a calibration device inside a scanning chamber of the scanning device, the chamber being intersected by at least one fan beam of x-rays during a scanning operation, measuring a distance between the calibration device and at least one inner wall of the chamber, scanning the calibration device to produce an image of the calibration device, identifying pixels representing the a geometric feature of the calibration device in the image, determining a position and orientation of the pixels representing the geometric feature in the image and, determining a scanning system property based on the position and orientation of the pixels representing the geometric feature in the image. The position and orientation of the feature in the scanning chamber and the x-ray scanning system property may be determined simultaneously.