This standard applies to security screening systems that utilize x-ray or gamma radiation and are used to inspect people who are not inside vehicles@ containers@ or enclosures. Specifically@ this standard applies to systems used to detect objects carried on or within the body of the individual being exposed. The following types of systems are included in the scope of this standard: ?? Systems designated as fixed@ portal@ re-locatable@ transportable@ mobile@ or gantry. ?? Systems employing detection of primary radiation (transmission systems)@ or scatter radiation (backscatter systems)@ or a combination of both. ?? Systems that are primarily imaging but that also may have complementary features such as material discrimination@ or automatic active or passive threat alerts. This standard will not address how to test these complementary features. Purpose The purpose of this standard is to provide standard methods of measuring and reporting imaging quality characteristics and to establish minimum acceptable performance requirements for the systems described in 1.1.