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Fm-cw Electromagnetic Technique of Measuring Coal Layer Thickness.

Authors
Ellerbruch-DA; Belsher-DR
Source
NTIS: PB 258 324 Available for Reference At Bureau Libraries :32 pages
Link
NIOSHTIC No.
10008280
Abstract
An fm-cw microwave system was investigated for measuring coal layer thickness. Measurements were made in three mines near Pittsburgh, Pennsylvania, Fairview, West Virginia, and Coffeen, Illinois. Microwave frequencies in the range 1 to 2 ghz were used to measure samples up to 55 cm thick. All samples were backed with a naturally occurring shale. Measurements were also made on coal and shale samples compounded in the laboratory. The dielectric constant of coal apparently varies significantly within a coal seam. The form of the output signals from the fm-cw system seem to simplify the data interpretation and analysis process compared with the manually swept microwave system used previously. It appears that this technique has the potential of measuring changes in the dielectric constant of a coal seam and providing an output that can be used for real-time corrections in layer thickness measurement.
Publication Date
19760101
Document Type
CP; Final Contract Report;
Fiscal Year
1976
NTIS Accession No.
PB-258324
NTIS Price
A04
Identifying No.
OFR 68-77
NIOSH Division
PRC;
Source Name
NTIS: PB 258 324 Available for Reference At Bureau Libraries
State
IL; PA; VA; WV;
Performing Organization
Nat'l Bureau of Standards
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