| 摘要 |
This invention relates to weighing apparatus of the electromagnetic load compensation type including a load or compensation coil connected with the load receiving member, and a reference coil connected with the frame for movement independent of the load receiving member, characterized in that the load and reference coils are arranged within separate air gaps of the magnetic field produced by a permanent magnet system mounted on the weighing apparatus frame. In one embodiment, the permanent magnet system includes a permanent magnet having a rotationally symmetrical field, and a magnetic yoke arrangement including an annular outer pole shoe arranged in concentrically spaced relation about an inner pole shoe. An annular ferromagnetic member is arranged in concentrically spaced relation between the inner and outer pole shoes for defining the air gaps in which the reference and load coils are arranged, respectively. In a second embodiment, the permanent magnet system includes a yoke having an annular outer pole shoe arranged in concentrically spaced relation about an inner pole shoe, the permanent magnet system including an annular arrangement of permanent magnets arranged in concentric spaced relation between the inner and outer pole shoes.
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