| 摘要 |
<p>The invention relates to a second-rank SQUID gradiometer and to a calibration method. According to one embodiment of the invention, the gradiometer comprises a complex SQUID transducer () comprising, in its turn, a SQUID sensor () magnetically coupled to a flux transformer () including in its structure three superconductive measuring coils () which are connected to form a structure of second-rank gradiometer of the magnetic field, these coils being arranged axially in parallel planes and being serially connected to an input coil () which is inductively coupled to the SQUID sensor () for performing calibration, operation control and gradient measurement by a zero method, on top of the measuring coils () there being three magnetic field generating coils () wherethrough some electric currents having the intensities I, Iand Icirculate and generate through the measuring coils () some fluxes PHI, PHIand PHIproportional with the current intensities, while through the flux transformer () a current having the intensityΔI will circulate to produce a magnetic flux variation through the input coil (), which leads to the generation, at the terminals of the SQUID sensor (), of a voltage which is processed by an electronic block (). The control and calibration of the gradiometer are carried out by a digital module () comprising a digital keyboard () by means of which the functions to be executed are selected and the initial data are introduced, a digital display device (), a micro system () processing the received information and controlling, by means of three constant current sources (), the injection of electric currents into the field generating coils (), while a digital communication interface () provides communication between the micro system () and the electronic block () and a computer ().</p> |
