Authority: IC 16-41-35-26; IC 16-41-35-29

Affected: IC 16-41-35

Sec. 49. As used in this rule, "half-value layer" means the thickness of a specified material which attenuates the beam of radiation to an extent such that the exposure rate is reduced to one-half (1/2) of its original value. The contribution of all scattered radiation, other than any which might be present initially in the radiation beam concerned, is excluded from this definition.

(Indiana Department of Health; 410 IAC 5-6.1-49; filed Oct 29, 1993, 5:00 p.m.: 17 IR 361; readopted filed Jul 11, 2001, 2:23 p.m.: 24 IR 4234; readopted filed May 22, 2007, 1:44 p.m.: 20070613-IR-410070141RFA; readopted filed Sep 11, 2013, 3:19 p.m.: 20131009-IR-410130346RFA; readopted filed Nov 13, 2019, 3:14 p.m.: 20191211-IR-410190391RFA; readopted filed Nov 14, 2025, 11:18 a.m.: 20251210-IR-410240588RFA)