A STUDY ON ALLOY COMPENSATION IN ISOTOPE THICKNESS MEASUREMENT OF STEEL

摘要

Alloy compensation is a key factor of isotope thickness measurement instruments used in iron and steel industry. Those instruments are all calibrated by a type of steel plate, for example, iron plate. There are apparent errors when the instruments measure an alloy of different composition to that of the calibration samples. In this paper, the problem is analyzed with the ultimate principle of Radiation Science and a formula to calculate the alloy compensation coefficient is presented. An experiment used a cobalt-60 source is done. The calibration samples are iron plates and the measured alloy is type-304 stainless steel. A simulation model based on the experiment instruments is built by a Montel Carlo program. Good agreement has been observed between theoretical, experimental and simulated results. In addition, thickness, energy of source and chemical composition of the alloy are the main factors of the compensation. The paper introduces how they related to the compensation coefficient.