Full definition
System that detects ferrous and non-ferrous metal objects embedded in a conveyor belt load to protect downstream equipment (mills, crushers, presses). Operates by electromagnetic induction: emits an alternating field and detects distortions. Adjustable sensitivity (e.g., detects a 30 mm ball at 800 mm depth). Triggers automatic belt stop or diverter. Brands: Eriez, Goring Kerr (Thermo Fisher).