Abstract: A magnet assembly for measurement of displacement of a rod is formed as a ring encircling the rod. The rod is displaceable along its axis and perpendicular to a plane of the ring. The rod includes a collar for interaction with a magnetic field produced by the magnet assembly. The assembly includes a magnetic field sensor and a first permanent magnet disposed along an inner surface of the ring, which are diametrically opposed on opposite sides of the rod. Second and third permanent magnets of like polarity are also disposed along the inner surface of the ring, and symmetrically positioned relative to the first magnet.

Abstract: In a device for electrically monitoring oil level, particularly in automobile internal combustion engines, a first temperature-dependent resistance element (1) is housed within a hollow space in an oil measurement rod and positioned at the height of a filling level. The device signals a dropping of the oil level below the filling level. A first resistance element is connected to an evaluation circuit having a source of current (17-23, 26, 27). A second temperature-dependent resistance element (16) is located in the oil measurement rod at a lower point than the first temperature-dependent resistance element (1). In order to be able to monitor the oil level over a large temperature range, the second temperature-dependent resistance element (16) can be switched to the evaluation circuit (emitter resistor 19) for correction of a switching threshold of the evaluation circuit as a function of temperature.