| 摘要 |
PURPOSE:To make it possible to measure the thickness without destruction highly accurately, by performing computation by utilizing the gamma-ray transmission quantity of laminated materials to be measured and the gamma-ray attenuation characteristics of the standard product of said materials. CONSTITUTION:gamma-rays having plural kinds of energies are generated by a gamma-ray source 2. The quantity of each energy projected on laminated materials 1 having different materials from the gamma-ray source 2 and a pulse signal obtained by a gamma-ray transmission-quantity detector 3 are discriminated 4 and 5 based on the difference in wave heights. The doses of transmission obtained by counting 6 and 7 the discriminated pulses are supplied to an operating device 8. The device 8 measures the thickness of each material based on the mass absorbing coefficient, which is obtained based on the projected gamma-ray energy and the gamma-ray attenuating characteristics of the standard project of said materials, and the density of said materials. |
