System 3000 reliably protects stone crushers, waste compactors, mills and other processing plant which could be damaged by larger metal parts. The MDV/MDVH analysis devices of system 3000 feature automatic calibration, self-monitoring, sensitivity potentiometer and test function. Some types feature attenuation indication and a test button.The devices are robustand water-tight and can be installed outdoors. To increase sensitivity or range, it is also possible to connect several coils to an analysis device.