Coal Mine Dust Incombustibles Content Analyzer Using a Gamma-ray Backscatter Technique.
NTIS: PB 234 696 :10 pages
An instrument using a gamma-ray backscatter technique for determining the weight-percent incombustibles content of coal dust and rock dust mixtures in coal mines has been built and tested. The unit gives a direct readout in percent incombustibles for coal mine dust mixtures containing between 50 and 100 percent incombustibles. Calibration of the device requires using a sample of the rock dust employed; the sample is usually limestone but is occasionally dolomite or gypsum. A small americium-241 source is used with a scintillation detector, the output of which feeds a rate meter. The source-detector geometry used was chosen to reduce the effects of variation in bulk density. Accuracy of the system is within +/-3 percent for most mixtures. The instrument is portable and completely self-contained; the rechargeable batteries supply power for 300 to 400 determinations.
IH; Report of Investigations
NTIS Accession No.
NTIS: PB 234 696