The principal of Alu-scanning made the material Foil Materials semi-magnetic with two search head on the running conveyor
And will transmit this magnatic signal of aluminum foil to the 2nd search head then the 2nd search head will detect metal particles.
Inside the aluminum foil after filtering the semi-magmetic.
And it will detect metal particle Such as Ferrous Steel or Stainless sagely in the running conveyor line.