NAC459.450. “Half-value layer” defined.

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“Half-value layer,” abbreviated as “HVL,” means the thickness of specified material which attenuates the beam of radiation to an extent that the exposure rate is reduced to one-half of its original value. In this definition the contribution of all scattered radiation, other than any which may be present initially in the beam concerned, is considered excluded.

[Bd. of Health, Radiation Control Reg. § 6.2.25, eff. 2-28-80]—(NAC A 4-27-84)

                    
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