Toward more testable security equipment

An important functional aspect of most security related equipment is the need for periodic performance testing. Sensors, entry-control devices, and other such security equipment usually have some sort or reliability or testing requirements. Unfortunately, testing requirements are seldom considered during equipment design, and testing becomes a prohibitively expensive or inconvenient afterthought. In this paper work at Sandia National Laboratories to address this concern is presented, focusing on metal detectors as a test case. Field testing of metal detectors is usually done by passing a test object through the opening to see whether an alarm is generated or not. Such alarm/no-alarm data are poor for making reliability estimates, and thus, a large quantity of such data is required to make good reliability statements. The detector itself uses much better internal information. Experiments tapping into some of this internal data will be discussed, and conclusions will be drawn about the possibility of redesign of metal detectors for enhanced testability. Such conclusions have implications for other types of security-related devices, as well