METHOD AND PICK-UP FOR CHECKING OF HIDDEN BOUNDARY COAL-ROCK

摘要

Method for checking of the hidden boundary coal-rock providing for irradiation of the checked medium (M) by a gamma radiation source (1) and sensing by a detector (2) of the reflected radiation effected at a distance (A) from the surface of the checked medium (M) and at a distance (B) from the radiation source (1). Two reflected radiation detection zones (Z1, Z2) differently distanced from the radiation source are formed on the detector (2) so that the intensity of the radiation detected at the zone (Z1) nearest to the source (1) decreases with an increase in the distance (A) from the detector (2) to the checked medium (M), and that detected at the zone (Z2) distant from the source-increases. The intensities of the reflected radiation detected at the two zones (Z1 and Z2) are added so as to obtain the total intensity which is invariant to the change of the distance (A) from the detector (2) to the checked medium (M). A pick-up for implementation of the method comprises a casing containing, inside it, the gamma radiation source (1) and the detector (2) of the reflected radiation protected with a screen (3) provided with openings differently distanced from the source (1). The surface of the opening the most distanced from the source (1) is bigger than that of the closest opening, whereas the distance (B) from the source (1) to the detector (2) does not exceed a preset maximum distance (A2) from the detector (2) to the checked medium (M).