| 摘要 |
<p>PURPOSE:To remove a malfunction due to a vibration or the like and reduce the size of a magnetic powder detector by providing the detector with two magnets arranged so that they are parallel to each other and the poles with the same polarity oppose to each other and two magnetoresistive elements opposed to both ends of one of the two magnets so that their center lines coincide with one another. CONSTITUTION:A detector 10 is constructed by two magnets 11 and 12 arranged in parallel so that the poles with the same polarity are opposed to each other and two magnetoresistive elements 13 and 14 arranged so as to oppose both the ends of one magnet 11, all of which are integrated by a casing or a resin mold 15. The upper surface of the casing or the resin mold 15 is formed as a magnetism sensing surface 15a. When a magnetic powder is present on an upper region adjacent to the magnets 11 and 12, a horizontal component reduces and a vertical component increases as compared with the case where the magnetic powder is absent. Therefore, by detecting the components as resistance values in the directions of the magnetoresistive elements 13 and 14 by a processing circuit, the presence of the magnetic powder can be detected.</p> |
