Patent ID: 7627954

Claim:
A gravity gradiometer for measuring components of a gravity gradient tensor, comprising: at least one sensor mass for movement in response to the gravity gradient; a pivotal coupling for coupling the mass for pivotal movement relative to first and second transducers; the first and second transducers are positioned relative to the mass, whereby, in use, pivotal movement of the mass towards the first transducer corresponds with pivotal movement of the mass away from the second transducer and pivotal movement of the mass away from the first transducer corresponds with pivotal movement of the mass towards the second transducer; the first transducer comprising first and second coils of superconducting material, the first and second coils spaced apart and connected parallel the second transducer comprising at least a third coil of superconducting material connected parallel to the first and second coils of the first transducer; current flow between said coils under superconducting conditions, said current flow proportioned between said first and second coils to provide said first transducer with an effective spacing from said mass; and the first and second transducers being connected to a first SQUID device so as to provide a measure of a change in current in the first and second transducers caused by movement of the mass.