METHOD OF MONITORING A HIDDEN COAL-ROCK INTERFACE AND A TRANSMITTER FOR PERFORMING THIS METHOD

摘要

The method of monitoring a hidden coal-rock inter-face includes irradiating the medium being monitoring froma gamma-ray source and registering by a detector the int-ensity of backward scattered radiation at a spacing fromthe surface of the monitoring medium and at a spacing fromthe radiation source. There are formed at the detector twozones of reception or backward scattered radiation, diff-erently spaced from the source, so that the intensity ofbackward scattered radiation received by the zone closerto the source diminishes, and the intensity of backwardscattered radiation received by the zone more remotefrom the source grows with a growing spacing of the de-tector from the monitored medium. The intensities ofbackward scattered radiation at the two zones are summedup to obtain the summary intensity invariant with respectto a varying spacing of the detector from the monitoredmedium. The transmitter for performing the method comp-rises a housing acommodating a gamma-ray source and a de-tector of backward scattered radiation, enclosed in ascreen having made therein ports differently spaced fromthe source. The area of the port more remote from thesource is greater than the area of the less remote port,and the spacing of the source from the detector does notexceed a preset maximum value of the spacing of the detec-tor from the monitoring medium.