Mail Screening Test Piece

The UK mail screening test piece (MSTP) is now available to all cabinet and conveyor x-ray operators to allow them to verify the image quality of their mailroom x-ray machines. The MSTP was developed by the Home Office Centre for Applied Science and Technology (CAST), in association with CPNI, to monitor the image quality of mailroom x-ray systems. The MSTP is recommended for checking regularly that the x-ray system is performing to the expected standard; it does so in terms of: Single wire resolution; ability to resolve a single wire behind varying thicknesses of aluminium; Spatial resolution in the vertical and horizontal directions; Imaging metal sheets of varying thickness; Materials discrimination; Imaging powders of varying thickness; Imaging and penetration of paper and paper substitutes of varying thickness. The tests on the mail screening test piece are designed specifically to cover the full range in apability of both cabinet and conveyorized X-ray machines used for mail screening but also allow for advances that could be made to the technologies in future years.