Separation in the first stage can have different conditions of separation  and  Separation in any type of magnetic detector or magnetic metal detector such as pulse metal detector or VLF metal detector or TR metal detector… or magnetic detector or function generator or system with magnetic wave can be in The best condition for ferrous metal from non ferrous metal is in magnetic properties which is also called the difference between distinguishing valuable metal from worthless which is not the principle of professional separation in separate metal detectors because any type of magnetic detector or magnetic metal detector has the ability to separate and discriminate metals of the same class does not distinguish from each other and most of the time the magnetic detector or magnetic metal detector does not separate and discriminate the metals in the same group in depth And all types of magnetic metal detectors have separation and discrimination settings with VDI number in the Edit it still does not distinguish and discriminate the metals of the same group with high accuracy