| 摘要 |
PCT No. PCT/DK97/00070 Sec. 371 Date Sep. 2, 1998 Sec. 102(e) Date Sep. 2, 1998 PCT Filed Feb. 14, 1997 PCT Pub. No. WO97/30336 PCT Pub. Date Aug. 21, 1997A method of determining the density profile of a plate-shaped material M, the density of which varies discretely or continuously across the plate thickness, whereas the density at a specific depth of the plate M is preferably assumed to be constant. The inventive method employs X-rays or gamma -rays from a source K. The latter source K is placed on one side of the plate M, whereas at least two detectors T, F are arranged on the opposite side of the endless plate being advanced during the measuring in the longitudinal direction. A first detector T is preferably placed in the radiating direction of the source and measures the transmittent radiation through the plate M, and the second detector F is placed outside the radiating direction of the source K and measures the scattered radiation on partial volumes along the radiating direction of the source. Based on the signals measured by the detectors it is possible to measure the density in each individual partial volume. According to the invention a compensation has furthermore been carried out for multiple scattered radiation by the measured radiation being deducted from the multiple scattered radiation.
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