| 摘要 |
PROBLEM TO BE SOLVED: To make detection accuracy less affected by external metal other than the object of detection and improve detection accuracy.SOLUTION: A revolution speed sensor detects the revolution speed of a rotary element (a wheel) 1. The wheel 1 is provided with a plurality of protruding blades 2. The revolution speed sensor is arranged so as to be able to face each blade 2, and comprises an eddy current-type sensor unit 3 for detecting the passage of each blade 2, and a coil 5 provided on one end face 3a, facing each blade 2, of the sensor unit 3. The coil 5 comprises two planar coils which differ in the direction of winding and are arranged adjacent to each other on the one end face 3a of the sensor unit 3. |
