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Continuous Monitoring of Coal by a Neutron Moisture Meter.

Hall AW; Konchesky JL; Stewart RF
NTIS: PB 225 276 :18 pages
A nuclear method was developed for continuously and automatically determining the moisture content of coal flowing through a bin. Fast neutrons from a 1 curie americium-beryllium source penetrate the coal, are thermalized (slowed down) by hydrogen in the moisture, and are counted by a thermal neutron detector. The difference between the number of these thermal neutrons and those thermalized by dry coal (in a reference drum) is a measure of the moisture content of the coal. A materials handlings system was developed and in tests at a commercial coal preparation plant, moisture in coal was monitored continuously within 0.2 percent of values determined by conventional means. The meter responded rapidly to change in moisture content, making it adaptable to automatic process control, and was operated for 1 year without malfunction or recalibration. Shielding of the source by the coal kept the neutron flux level at the bin wall less than 1 milliroentgen per hour, a safe level for personnel. Work done in cooperation with the U.S. Steel Corporation.
Publication Date
Document Type
IH; Report of Investigation;
Fiscal Year
NTIS Accession No.
NTIS Price
Identifying No.
RI 7807
Source Name
NTIS: PB 225 276
Page last reviewed: December 10, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division