| 摘要 |
A measuring device such as a gravity gradiometer has a levitation coil (26) and a float body (12). The float body (12) is capable of being magnetically levitated by the coil (26) on a levitation axis (L) about which angular movement of the float body (12) relative to the coil (26) is to be detected. Angular motion of the float body (12) is effected using field-modulating strips (36) which are carried by the float body (12) and which are rotatable with the latter relative to pairs of coils (38, 40; 42, 44). The levitation coil (26) lies on the surface of a sphere. The float body (12) has a concave lift surface sensitive to levitational forces exerted by the levitation coil (26) in use. The lift surface also lies on the surface of a sphere. |
