1, The application of virtual instrument (VI) technique in Gradiometer control system test is studied.

2, A two-dimension gradiometer based on the principle of torsion measurement with a precision of 1E has been designed.

3, We checked that the output voltage of gradiometer has linear relation with first order differential of magnetic field.

4, It was found the maximum output voltage of gradiometer could be obtained while the two directions were parallel.

5, The airborne magnetic gradiometer came into use in the middle 1960 s.

6, An approach to measure biomagnetic field by using a SQUID second order gradiometer has been explored.

7, Gravity gradient is the order derivative of gravitational potential,(http:///gradiometer.html) which can be observed by satellite gradiometer.

8, Through the technical composition of hardware - software, virtual instrument ( VI ) -- gradiometer is realized.

9, Gravity gradient is the second order derivative of gravitational potential, which can be observed by satellite gradiometer.

10, It is showed by the experimental results that the influence of the background magnetic field is mostly eliminated, the precision is improved, and the stability of the gradiometer circuitry is good.

11, In this thesis we fabricated and discussed the performance of high Tc superconducting planar directly coupled first order Gradiometer.

12, Based on the gravity gradient measurement principle of rotating accelerometer gravity gradiometer, an online method of accelerometers scale factor adjusting is proposed in this paper.