OAR 333-122-0276: X-ray and Hybrid Gauges: Safety Device

(1) Except where impractical, an interlocking device which prevents the entry of any portion of an individual's body into the primary beam or causes the primary beam to be shut off upon entry into its path, shall be provided. (2) In cases where the primary radiation beam is not intercepted by the detector device under all conditions of operation, protective measures shall be provided, such as auxiliary shielding, to avoid exposure to any individual from the transmitted primary radiation.