Administrative Rules of Montana › Department 37 - PUBLIC HEALTH AND HUMAN SERVICES › Chapter 37.14 - RADIATION CONTROL › Subchapter 37.14.10 - X-Rays in the Healing Arts › Rule 37.14.1002 - DEFINITIONS

Current through Register Vol. 13, July 5, 2024
As used in this subchapter:
(1) "Aluminum equivalent" means the thickness
				of aluminum affording the same attenuation, under specified conditions, as the
				material in question.
(2)
				"Diagnostic-type tube housing" means an x-ray tube housing so constructed that
				leakage radiation at a distance of one meter from the target cannot exceed 100
				milliroentgens in one hour when the tube is operated at any of its specified
				ratings.
(3) "Enabling switch or
				momentary switch" means an underwriters laboratory (UL) or factory mutual (FM)
				switch so constructed that a single depression by the operator will provide a
				single exposure and that continuous pressure by the operator does not provide a
				continuous or multiple exposure.
(4) "Filter" means material placed in the
				useful beam to absorb preferentially the less penetrating radiations.
(5) "Half-value layer (hvl) " means the
				thickness of an absorber required to reduce a beam of radiation to one-half its
				incident exposure rate.
(6)
				"Inherent filtration" means the filtration in the useful beam due to the window
				of the x-ray tube and any permanent tube enclosure.
(7) "Interlock" means a device for precluding
				access to an area of radiation hazard either by preventing entry or by
				automatically removing the hazard.
(8) "Kilovolts peak (kVp) " means the crest
				value in kilovolts of the potential of a pulsating potential generator. When
				only one-half of the wave is used, the value refers to the useful half of the
				wave.
(9) "Lead equivalent" means
				the thickness of lead affording the same attenuation, under specified
				conditions, as the material in question.
(10) "Leakage radiation" means all radiation
				coming from within the tube housing except the useful beam.
(11) "NCRP" means the national council on
				radiation protection and measurements.
(12) "Primary protective barrier" means a
				barrier sufficient to attenuate the useful beam to the required
				degree.
(13) "Protective apron"
				means an apron made of attenuating materials used to reduce radiation
				exposure.
(14) "Protective barrier"
				means a barrier of attenuating materials used to reduce radiation
				exposure.
(15) "Protective glove"
				means a glove made of attenuating materials used to reduce radiation
				exposure.
(16) "Qualified expert"
				means a health physicist, medical physicist, radiologist, or other individual
				who can competently perform the calculations necessary to provide shielding
				requirements within the standards of this chapter.
(17) "Scattered radiation" means radiation
				that, during passage through matter, has been deviated in direction.
(18) "Secondary protective barrier" means a
				barrier sufficient to attenuate stray radiation to the required
				degree.
(19) "Shutter" means a
				device, generally of lead, fixed to an x-ray tube housing to intercept the
				useful beam.
(20) "Stray radiation"
				means radiation not serving any useful purpose. It includes leakage and
				secondary radiation.
(21)
				"Therapeutic-type tube housing" means an x-ray tube housing so constructed that
				the leakage radiation at a distance of one meter from the target cannot exceed
				one roentgen in one hour; and at a distance of five centimeters from any point
				on the surface of the housing accessible to the patient cannot exceed 30
				roentgens in one hour when the tube is operated at any of its specified
				ratings.
(22) "Useful beam" means
				that part of the radiation which passes through the window, aperture, cone, or
				other collimating device of the tube housing.
Sec.
					 50-79-201
					 and
					 75-3-201,
					 MCA; IMP, Sec.
					 50-79-101,
					 50-79-102,
					 50-79-103
					 and
					 75-3-201,
					 MCA;