We are undertaking a comparison of the relative performance of ANSI N42.46 and IEC 62523 consensus standards for x-ray cargo and vehicle screening. By performing each of the tests as specified in the standards, we can assess the practicality of their use under typical test conditions. By comparing the results we are able to assess how one standard performs in comparison to the other and whether significant differences or shortcomings exist in any of the test methods.
Test objects were fabricated according to the specifications given in the respective standards, and a support structure mounted to a tilt/lift platform was designed and built in order to place and orient the test objects inside an x-ray scanning device. Performance data have been obtained using a variety of air cargo and high-energy x-ray scanners used to screen tractor trailers at a U.S. port-of-entry, following the test methods prescribed in the two standards. Our results have revealed some important differences between the two standards, and the experience gained by the application of these standards in the field will be used to advise the standards committees on possible changes to the test articles and improvements or additions to the test methods, with the ultimate goal of achieving harmonization between national and international standards for security. The photograph (top right) shows ANSI test articles placed on the tilt/lift platform within the cargo bay of a high-energy cargo scanning system installed at a U.S. port-of-entry. The image (bottom right) is a digital radiograph obtained with this high-energy system for the ANSI penetration and spatial resolution tests. The tilt/lift platform is also seen in the image.