Magnetic properties of unrusted steel drums from laboratory and field-magnetic measurements
- Southern Illinois Univ., Carbondale, IL (United States). Dept. of Geology
Detection and precise location of buried ferromagnetic objects and estimation of the type and quantity of the objects are becoming increasingly important in environmental investigations worldwide. If laboratory-derived magnetizations were used to model steel drums, the models would under-estimate the resulting magnetic anomalies considerably and, in turn, would overestimate the number of buried drums at an environmental investigation site. Apparent bulk magnetization values for unrusted vertically oriented 55 and 30 gallon drums have been calculated (i.e., the values corrected for the effect of shape demagnetization of the drums). These range from {approximately}90 to {approximately}125 SI units for volume susceptibility and from {approximately} 325 to {approximately} 2,750 A/m for remanent magnetization (based on eight 55 gallon and four 30 gallon drums). Further deviations in these values could arise from the and thickness of the steel and variations in manufacturing conditions affecting magnetizations. From the point of view of modeling the drums, at most source-to-observation distances applicable to environmental investigations, the equivalent source method is able to approximate the observed anomalies of steel drums better than the 3-D modeling method. With two years of rusting, magnetic anomalies of some of the drums have reduced, while in other drums they have slightly increased. The overall magnetic changes caused by rusting appear to be more complex than anticipated, at least in the initial phase of rusting.
- OSTI ID:
- 404390
- Journal Information:
- Geophysics, Vol. 61, Issue 5; Other Information: PBD: Sep-Oct 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
COMBINED GEOPHYSICAL INVESTIGATION TECHNIQUES TO IDENTIFY BURIED WASTE IN AN UNCONTROLLED LANDFILL AT THE PADUCAH GASEOUS DIFFUSION PLANT, KENTUCKY
Criticality Evaluation for the Storage of Converter Plates in Drums