PURPOSE: To provide a proof mass supporting and sensing system to be used in a superconductor acceleration gauge or gravity gradient gauge.

CONSTITUTION: A proof mass supporting system is provided with a pair of alignment coils 42, 44 to control a stop position of thin proof masses 3, 4. These alignment coils 42, 44 are composed to provide floating force in carrying a current which is changed along length of the proof masses 3, 4. A means to tune relative strength of a current at the alignment coils 42, 44 is provided to set the proof masses 3, 4 in a specified direction to more than one freedom degrees determined by the alignment coils 42, 44. In another mode, more than one anti-rotation coils are composed to provide restoration force to the proof masses 3, 4 when the current passes, the proof masses are formed to cooperate with the restoration force, and the restoration force is set to act to prevent rotation of the proof masses from rotating apart from the specified direction. This system is normally provided as part of a superconductor acceleration gauge or gravity gradient gauge.