METAL DETECTOR TYPE GRS GRS Metal Detectors: Comprehensive Protection for Your Machinery GRS metal detectors are installed around the conveyor belt, detecting any type of metal mixed with materials to protect crushing machinery. Equipped with two coils (transmitter and receiver) and a control unit with microprocessor, they ensure high stability and sensitivity against vibrations and interference. They generate a constant electromagnetic field that is disturbed by passing metals, triggering the detection signal. Robust, reliable, and easy to install, with no mechanical maintenance required. CE Certified and available with Atex Zone 22 Ex-3D and Atex Zone 21 Ex-2D (optional). Metal-free zone: A= 1.5 D for moving metals (vibrating feeder). A= 2/3 D for non-moving metals.