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Effects of microscope objectives on magnetic field exposures
Author(s) -
Publicover Nelson G.,
Marsh Carl G.,
Vincze Craig A.,
Craviso Gale L.,
Chatterjee Indira
Publication year - 1999
Publication title -
bioelectromagnetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.435
H-Index - 81
eISSN - 1521-186X
pISSN - 0197-8462
DOI - 10.1002/(sici)1521-186x(199909)20:6<387::aid-bem8>3.0.co;2-#
Subject(s) - microscope , bioelectromagnetics , magnetic field , microscopy , nanotechnology , optics , materials science , physics , quantum mechanics
Distortions in magnetic field intensity generated by commonly used microscope objectives (1× to 100×) were characterized within a Helmholtz coil–based exposure system. Objectives from a variety of manufacturers distorted applied field intensities by up to 23% in the image plane. Components that contribute to distortions include (1) nickel‐chrome plating of objective housings, (2) the presence of steel springs in objectives with compression collars, and (3) steel screws or studs used to hold together separately manufactured parts. Steel springs and screws produce radially asymmetric profiles, whereas distortions generated by nickel‐chrome plating are typically radially symmetric. All components can produce spatial gradients in field intensity if objectives are not perfectly aligned with exposure systems or if placed in the earth's magnetic field. Alterations in the magnitude of magnetic field intensities as well as the production of spatial gradients might have an effect on biological responses. By maintaining optical glass components and replacing metallic components, functional objectives can be reconstructed that produce no measurable effects on magnetic flux densities. Bioelectromagnetics 20:387–395, 1999. © 1999 Wiley‐Liss, Inc.