MEASUREMENT FOR THICKNESS OF MULTI-LAYER LAMINATE MATERIAL

PURPOSE:To measure the thickness of a multi-layer laminate material by employing (n-1) pieces of radiation characteristic formulas obtained from the degree of the transmission attenuation and the formula for the overall thickness of the multi-layer laminate material when radiations in (n-1) kinds of energy levels are transmitted with (n) layers of the multi-layer laminate material. CONSTITUTION:A multi-layer laminate material 1 is a multi-layer steel plate of (n) layers made of different material and a radiation source 2 is arranged on one side thereof to generate radiations in (n-1) kinds of energy levels while a radiation detector 3 is arranged on the other side thereof. A radiation Ioi is transmitted with the multi-layer laminate material 1 from the radiation source 2 to detect the transmission level Iti with a radiation detector 3 and (n-1) pieces of radiation characteristic formulas are obtained. In addition, a formula is obtained to measure the overall thickness of the multi-layer laminate material by other method than the radiation transmission and in total, (n) pieces of simultaneous equations are established to calculate tj to measure.