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.
Test objects, as specified in the respective standards, have been fabricated and we are now seeking suitable facilities to conduct field tests with these objects, following the test methods prescribed in the standards. One such test method involves the determination of the maximum penetration of the x-ray imaging system. The photograph shows a lead total absorber, supported by a steel plate, used for the IEC 62523 steel penetration test method. Once the relevant test data have been obtained for each of the standards, their relative performance will be compared. Since the test methods of the two standards have some distinct differences, it will be interesting to observe whether this results in different values of the x-ray parameters when they are applied. By performing each of the tests as specified in the standards, we will be able to comment on the practicality of their use under typical test conditions. Comparison of the results will allow us to assess how each performs against the other and whether significant differences or shortcomings exist in any of the test methods. While direct field application of the standards is essential, whenever possible we would like to conduct our own objective analysis of the images to determine whether our test results differ from those obtained in the field. We plan to perform these tests using both low energy systems designed for air cargo and high energy systems used for vehicle screening. This will allow us to determine whether differences exist between the two test methods with regard to the type of system used. Upon completion of the comparisons we will be able to recommend possible changes to future versions of the standards, with a goal towards harmonization.