410 IAC 5-6.1-11 "Aluminum equivalent" defined

Sec. 11. As used in this rule, "aluminum equivalent" means that thickness of type 1100 aluminum alloy (compounded of ninety-nine percent (99%) aluminum, minimum, and twelve-hundredths percent (0.12%) copper, minimum) which affords the same attenuation as the material in question, under the same conditions.