| 摘要 |
The device (100) exhibits a coil (1) through which alternating current flows and a magnetisable core (2). The coil (1) is surrounded by a magnetisable sleeve (3) and fixed in the sleeve (3) by end discs (4, 4') of non-magnetisable material, arranged at its ends and spanning the radial distance between the core and the sleeve. The sleeve and the core are magnetically connected to one another at the end which faces away from the movable part (40) to be scanned. The sleeve (3) is surrounded at least over some of its length at the end facing the movable part (40) by a magnetisable bush (5) which exhibits at its end facing the movable part a disc-shaped closing cover (6). This cover consists of a non-magnetisable annular disc (7) which spans the end face of the sleeve (3) and at least some of the radial distance between the core (2) and the sleeve (3), and a central magnetisable disc (8) located in front of the end face of the core. This improves the sensitivity of the scanning device in a simple and inexpensive manner. <IMAGE> |
