Measurement of very small magnetic field gradients using SQUID devices, whereby a magnetometer SQUID with a feedback look is used to compensate background field variations and a gradiometer SQUID is used to measure the gradient

摘要

Method for measuring a magnetic field gradient in which the background magnetic field is maintained constant by use of a magnetometer (3) with a feed back loop. An independent claim is made for a device (1) for measuring a magnetic field gradient with a gradiometer (2) and a magnetometer arranged adjacent to each other. The magnetometer has a feedback loop in order to generate a constant homogeneous background magnetic field around the gradiometer. The invention relates particularly to the use of SQUID (super-conducting quantum interference device) devices as both gradiometer and magnetometer with both arranged in the same plane.