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A Photographic Method for Determining Mineral Reflections in Underground Coal Mines.

Authors
Mayton-AG
Source
BoM, 1986 Jun :14 pages
Link
NIOSHTIC No.
10005816
Abstract
The Bureau of Mines conducted a study to (1) determine from laboratory tests the feasibility of a photographic method for determining reflectances that may be applied to measuring in-mine mineral reflectances and (2) formulate a procedure for collecting and analyzing the data. The method uses a 35-mm camera with automatic flash and a gray-scale reflectance standard to collect on film reflectivity data in underground mineral mines. After the film is processed, the data on the photographic prints are analyzed in the laboratory with a photometer. Test results show that the photographic method can provide values of reflectance within +/- 5 pct of full scale (full scale = 100 pct). The method's usefulness for determining reflectivity values within similar limits of absolute percent error at the lower end of the scale, however, has not been completely resolved by the study and consequently warrants further investigation. The method offers an acceptable means for collecting and analyzing reflectivity data for reflectivities at the higher end of the scale, i.e., 50 pct or above; it should be used with caution when reflectivity values are below 50 pct. Four films were evaluated; all gave relatively satisfactory results.
Keywords
Safety-engineering; Photographic-techniques; Coal-mining; Underground-mining; Photographic-analysis; Mine-lighting; Mineral-industries;
Publication Date
19870601
Document Type
IH; Report of Investigations;
Fiscal Year
1987
NTIS Accession No.
PB88-232525
NTIS Price
A03
Identifying No.
RI 9107
NIOSH Division
PRC;
Source Name
Bureau of Mines, Pittsburgh, Pennsylvania
State
PA;
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