| 摘要 |
1,185,783. Radiation inspection of paper. VALMET OY. March 28, 1968 [April 1, 1967], No. 14948/68. Heading G1A. The total filler content of a sheet of paper or the distribution of filler material across the thickness of a sheet of paper is determined by measuring the intensity of X-rays excited from the material by primary radiations which areαor # radiations which have different penetration powers and whose intensities are varied to penetrate the paper to varying depths. The paper sheet may be a travelling web during the paper manufacture or a laboratory sample. Characteristic X-rays from different elements of the filler material are distinguished by means of Ross filters or pulse height analysis of the X-ray detector output. The detector, which may be a scintillation, proportional or Geiger counter is on the same side of the sheet as a radio-active source of the primary radiation and is shielded from it. Measurements are taken from both sides of the sheet. |
