| 摘要 |
PURPOSE:To detect metal mixed in a product at high sensitivity by arranging two opposing receiving coils to make the number of interlinkage equal to magnetic flux of a transmitting coil in which DC current is let flow and passing the product which is excited beforehand. CONSTITUTION:Two receiving coils 41, 42 are arranged opposite to a transmitting coil 3 connected to a DC power source to make the number of interlinkage equal to magnetic flux. The product is carried by a conveyor 1, and magnetic substance contained in the product is magnetized just under a magnetizing device 2 consisting of an exciting coil. Then, the product is carried in a detecting head 6, and if there is any magnetic substance, difference is generated in induced voltage as the number of interlinkage of magnetic flux of the receiving coil changes. This unbalanced signal is indicated as a metal detecting signal through a controlling circuit 7. |
