An accelerometer comprises a housing defining a chamber, a magnetizable fluid within the chamber, an electrically conductive, hollow cylindrical proof mass suspended within the chamber so as to be displaceble from a null position along a displacement axis by an applied force, and a sensing arrangement including electrodes on the inside wall of the chamber for detecting displacement of the proof mass along the displacement axis and for supplying an electrical signal indicative of the applied force. The proof mass is substantially non-magnetic, and magnets are disposed outside the chamber for magnetizing the magnetizable fluid to cause the proof mass to be suspended within the chamber by the fluid. Since there is no requirement for the proof mass to itself be magnetic as in prior accelerometers, it follows that there is no magnetic interaction between the magnetized particles of the fluid and the proof mass, and thus the effective mass of the proof mass will be substantially unchanged by changes in the distribution of the particles. Restoring coils are provided to restore the proof mass to a null position by inducing current flow in the proof mass.
展开▼
