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Induced electric currents in the Alaska oil pipeline measured by gradient, fluxgate, and SQUID magnetometersThe field gradient method for observing the electric currents in the Alaska pipeline provided consistent values for both the fluxgate and SQUID method of observation. These currents were linearly related to the regularly measured electric and magnetic field changes. Determinations of pipeline current were consistent with values obtained by a direct connection, current shunt technique at a pipeline site about 9.6 km away. The gradient method has the distinct advantage of portability and buried- pipe capability. Field gradients due to the pipe magnetization, geological features, or ionospheric source currents do not seem to contribute a measurable error to such pipe current determination. The SQUID gradiometer is inherently sensitive enough to detect very small currents in a linear conductor at 10 meters, or conversely, to detect small currents of one amphere or more at relatively great distances. It is fairly straightforward to achieve imbalance less than one part in ten thousand, and with extreme care, one part in one million or better.
Document ID
Document Type
Conference Paper
Campbell, W. H. (Geological Survey Denver, CO, United States)
Zimmerman, J. E. (NBS Boulder, Colo., United States)
Date Acquired
August 10, 2013
Publication Date
December 1, 1979
Publication Information
Publication: NASA. Marshall Space Flight Center Solar-Terrest. Predictions Proc., Vol. 2
Subject Category
Distribution Limits
Work of the US Gov. Public Use Permitted.
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