| 摘要 |
PURPOSE:To measure the clearance between magnetic materials from above, by previously saturatedly magnetizing one of the magnetic materials by means of a DC magnetic flux before making the clearance measurement so that an AC magnetic flux for measurement can pass through the other magnetic material across the clearance. CONSTITUTION:In order to measure the very narrow clearance S between a pressing mold 1 and pressed product 2, magnetic cores 4 and 5 fixed to both end sections of a permanent magnet 3 are contacted with the pressed product 2 and the product 2 is saturatedly magnetized in advance. Under this condition the AC signal of a transmitter 6 supplied through an amplifier 7 is impressed upon the primary coil 8 of the magnetic core 4. The AC magnetic flux passes through the pressing mold 1 across the pressed product 2 which becomes just like a nonmagnetic material due to the saturated magnetism and the clearance S and induces a prescribed voltage across the secondary coil 9 of the magnetic core 5. An output value detected by the secondary coil 9 is displayed as a clearance size in a meter 12 through an amplifier 10 and corrector 11.
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