Abstract
An extraordinary magnetically shielded room was designed and constructed for the Physikalisch-Technische Bundesanstalt Institut Berlin to measure extremely weak magnetic fields of the human body with SQUID-magnetometers. The inner and the outer dimensions of the cube-shaped room are 2.25 m and about 5 m. The shield has 6 magnetic shells of a high-permeability alloy and an inner shell welded of massive copper plates. The total weight of the magnetic alloy is about 10 t and about 5 t for the inner copper shell. The required shielding factor of 1000 for the very low frequencies was greatly surpassed by the real measured value of 10000 (measured without any compensating or idealizing method). With rising frequencies the shielding factor reaches higher values, at 50 Hz more than 100000 and a million for 1000 Hz. First measurements in the shielded room with high-resolution magnetocardiograms (HR MCG) and high-resolution electrocardiograms (HR ECG) showed new methods for non-invasive electrophysiological investigations in man.
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References
Cohen, D.: Rev. Phys. Appl. 5, 53 (1970)
Kelhä, V., in: Biomagnetism, p. 33 (Erné, S.N., Hahlbohm, H.-D., Lübbig, H., eds.). Berlin-New York: de Gruyter 1981
Kelhä, V., et al.: IEEE Trans. Magn. 18, 260 (1982)
Boll, R.: Weichmagnetische Werkstoffe (Vacuumschmelze GmbH, Hrsg.). Berlin-München: Verlag Siemens AG 1977
Mager, A.: J. Magn. Magn. Mat. 2, 245 (1976)
Patentschrift DE 24 46 986 C3, Anm. 2. 10. 74, Veröff. 27. 8. 81
Vacuumschmelze GmbH: Magnetische Abschirmungen. Hanau 1975
Mager, A., in: [2]
Kaden, H.: Wirbelströme und Schirmung in der Nachrichtentechnik. Berlin-Göttingen-Heidelberg/München: Springer/Bergmann 1959
Mager, A.: IEEE Trans. Magn. 6, 67 (1970)
Kaden, H.: Frequenz 24, 27 (1970)
Mager, A.: Forschungsbericht BMFT-FB T 79-32. Eggenstein-Leopoldshafen: FIZ Energie, Physik GmbH 1979
Erné, S.N., et al., in: [2]
Erné, S.N., et al., in: [2]
PTB, Inst. Berlin: Pressemitteilung. Berlin 12. 11. 1981
Fenici, R.R., et al.: Vortrag 5 ° Seminario Internazionale di Cardiologia. Trento, Italien, 1982
Mager, A.: Zur optimalen Dimensionierung von Mehrfachabschirmungen. Interner Bericht, Vacuumschmelze GmbH Hanau: E-Dr.Mg/Eb Nr. 91/74, 1981
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Mager, A. Magnetisch abgeschirmte Kabine zur Aufnahme kleinster magnetischer und elektrischer Biosignale. Naturwissenschaften 69, 383–388 (1982). https://doi.org/10.1007/BF00396689
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DOI: https://doi.org/10.1007/BF00396689