The Merlin Contraband Detector is a portable, lightweight instrument that indicates the presence of hidden material by signalling unexpected changes in the density or thickness of a surface. For example, an ‘empty’ tyre filled with air will register a lower reading than one filled with drugs. As the Detector is moved across the surface of the object the measured backscatter is displayed on an LCD digital readout and an alarm sounds if the reading changes. The Merlin Contraband Detector also features a unique radiation detection function which allows the instrument to detect the presence of concealed radioactive material. Audio output resembles a traditional Geiger counter in this mode. Two extension arms are available, with 400mm (16”) and 3m (10’) operational length; allowing inaccessible surfaces to be searched, such as the insulated walls of high sided vehicles or ceilings within buildings. A remote display/control unit allows the operator to see and control all of the electronic functions of the instrument when using either of the extension arms or simply when the main unit is inconveniently placed (e.g. under a car).