[Retracted] Nondestructive Testing of Coal Mine Wire Ropes Based on Magnetic Sensors

Table 1

Dimensions of each part of the sensor.

Sensor structure parameters
Wire diameter	Internal distance of armature	Radial thickness of armature	Distance between wire rope and armature inside	Axial length of permanent magnet	Radial length of permanent magnet	Air gap
8	40	2	30	15	25	3
16	60	4	30	15	25	3
32	75	4	40	15	25	3
40	90	6	40	15	25	3