POSITION DETECTION SENSOR

PROBLEM TO BE SOLVED: To restrict detection error of a running position to the minimum by detecting inclination of a detection coil to the ground surface, and correcting the inclination. SOLUTION: A position detection sensor comprises an oscillation circuit unit 1, a coil unit 2, a preamplifier unit 3, a positioning sensor amplifier unit 4, and a coil attitude control part. The coil unit 2provided on a sensor head comprises an active coil 21 to detect a mark plate, and a compensation coil 22 for a reference signal. Each of the active coil 21 and the compensation coil 22 comprises an excitation coil 23 and a detection coil 24. On the sensor head, a photoelectric sensor is provided as a detection means to detect inclination of the excitation coil 23 and the detection coil 24 to the ground surface. The coil attitude control part regulates an adjusting screw by a stepping motor in accordance with the inclination detected by the photoelectric sensor to correct the inclination of the coil unit 2.