Open AccessCalculation of Parameters for the Astatic Magnetometer
Author(s) -
Ispir Yilmaz
Publication year - 1971
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1971.tb03600.x
Subject(s) - magnetometer , ellipsoid , magnet , demagnetizing field , sensitivity (control systems) , physics , signal (programming language) , noise (video) , transverse plane , mathematical analysis , geometry , magnetization , optics , nuclear magnetic resonance , magnetic field , mathematics , engineering , electronic engineering , structural engineering , computer science , quantum mechanics , astronomy , artificial intelligence , image (mathematics) , programming language
Summary The sensitivity and the signal‐to‐noise ratio of an astatic magnetometer are proportional to the intensity of magnetization of each magnet in the suspended system. Hitherto the intensity of magnetization has been calculated using values of demagnetization factors for ellipsoids and have been applied to astatic design incorporating rectangular or cylindrical magnet forms. In the present paper, the magnetizations of both rectangular and cylindrical magnets have been calculated again using more exact values of the demagnetization factors for rectangular and cylindrical shapes, respectively. Then the calculated parameters for the astatic magnetometer in this study are compared with the previous calculations to show the effect of the demagnetization factors for ellipsoids on the theoretical calculations in the astatic design incorporating rectangular or cylindrical magnets. It is shown that the theoretical values of both sensitivity and signal‐to‐noise ratio of an astatic magnetometer are sensitivity (ellipsoid approx.)/sensitivity (exact shape) = 1.5; and signal‐to‐noise (ellipsoid approx.)/signal‐to‐noise (exact shape) = 2.0. These are lower than the values in previous calculation in the case of longitudinal magnets. But this previous assumption is not significant for transverse magnets, say FEROBA III.