TOR ABC is a routine test object used for beam alignment and centring in radiography and fluoroscopy. Also a special variant of the vertical bucky jig is available for Siemens’ Vertix system.
•The correspondence of the light field with the effective radiation field
•The determination of the position of the central beam
•The central beam angle deviation from 90°, relative to the plane of the film/detector, is below a limit beyond which the image quality would be adversely affected