Coin testing by inspection of the coin surface and edges using a magnetic field generated on either side of the coin so that the surface impressions can be accurately scanned by changes in the magnetic field

摘要

Device comprises detection coils for production of a double peak magnetic field. First and second detection coils (1a, 1b) are arranged on two adjacent leg parts (6b, 6c; 6b', 6c') of a chamber type core with a number of core leg parts (6a-6c; 6a'-6c') arranged at regular intervals. The coils are then excited so that overlapping detection magnetic fields are produced. An Independent claim is made for a procedure for use with the above device in which a coin is passed through the magnetic field generated by the coils and the change in the magnetic field caused by the coin is used to test the surface and edge of the coin.