| 摘要 |
PURPOSE:To determine easily and accurately the surface density of a material such as atoms and pigment by measuring photographic density through an X-ray film, by irradiating a thin plate, original paper applied with pigment, etc., including metal atoms, with X-rays produced by two fixed selected bulb voltages. CONSTITUTION:On original paper 5a such as paper and a plastic film, pigment 5b such as calcium carbonate is applied, charged or laminated to form thin plate 5. This thin plate 5 is irradiated with X-rays by selecting X-ray bulb voltage greater and less than the maximum value of mass absorption coefficient mub of calcium carbonate, thereby measuring through X-ray film 5 the photographic density by transmitted X-rays. Next, the condition, mua1mub2-mub1mua2 0, is satisfied on the basis of equation I to determine accurately surface density values Wa and Wb of the original paper and calcium carbonate. Further, when the photographic density is measured by irradiating atoms and pigment independently with X-rays by bulb voltages nearly equal in absorption coeffcient, the surface density of the thin plate of them is determined. Here, I1, I01, I2 and I02 represent actually-measured absorbance. |
