| 摘要 |
PROBLEM TO BE SOLVED: To discriminate accurately the kind or truth of a metal body to be detected such as a coin or the like by detecting individually each information such as the quality of material, the thickness or the like. SOLUTION: In this U-shaped magnetic sensor 1, projection parts 2 are formed so that two free ends thereof are faced each other, and exciting coils 3 and detection coils 4 are wound respectively on the projection parts 2, and the metal body to be detected 5 is conveyed between the two projection parts 2 to detect the metal body to be detected 5. When a pair is formed from two U-shaped magnetic sensors 1, one magnetic sensor 1 is used as a detection magnetic sensor 1a for detecting the metal body to be detected 5, and the other magnetic sensor 1 is used as a reference magnetic sensor 1b, and thereby a differential output is detected and more accurate discrimination can be executed.
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