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and is capable of measuring ionizing radiation of the energies and at the dose rates to be encountered, and that has been properly calibrated within the preceding three months or following the last instrument servicing, whichever is later. Survey results and records of boundary locations must be retained for at least five years, or since the most recent inspection by the department, whichever is less. (Eff. 4/9/2009, Register 190) Statutory Authority: Authority: AS 18.60.475 AS 18.60.485 Article 6. Definitions. Rule 7 AAC 18.990. Definitions 7 AAC 18.990. Definitions. Unless the context requires otherwise, in this chapter,

(1) “absorbed dose” means the energy imparted by ionizing radiation per unit mass of irradiated material, and a unit of which is the rad and the gray;

(2) “activity” means the rate of disintegration, transformation, or decay of radioactive material, and for which a unit of activity is the curie and the Becquerel;

(3) “airborne radioactive material” means radioactive material dispersed in the air in the form of a dust, fume, mist, vapor, or gas;

(4) “aluminum equivalent” means the thickness of aluminum allowing, under specific condition, the same attenuation as the material in question;

(5) “Becquerel” means a unit for the measurement of radioactivity that is equal to one disintegration per second;

(6) “bioassay” means the determination of kinds, quantities, concentrations, and locations of radioactive material in the human body, by direct measurement, in vivo counting, or by analysis and evaluation of materials excreted or removed from the human body;

(7) “C-arm” means a kind of mobile fluoroscope that allows for quick repositioning of the radiation tube during use;