DHS 157.03(152)(152) “Guide tube” means a flexible or rigid tube, for guiding the source assembly and the attached control cable from the exposure device to the exposure head. The guide tube may also include the connections necessary for attachment to the exposure device and to the exposure head. DHS 157.03(153)(153) “Half-value layer” or “HVL” means the thickness of specified material which attenuates an x-ray or gamma radiation beam such that the air kerma rate at a point within the radiation beam is reduced to one-half of the air kerma rate at the same point without the material present. In this definition, the contribution of all scattered radiation, other than any that might be present initially in the radiation beam concerned, is excluded. DHS 157.03(154)(154) “Hands-on experience” means experience in all of those areas considered to be directly involved in the radiography process. DHS 157.03 NoteNote: “Hands-on experience” includes taking radiographs, calibration of survey instruments, operational and performance testing of survey instruments and devices, film development, posting of warning signs in radiation areas, transportation of radiography equipment, posting on a bulletin board of records and radiation area surveillance, as applicable.
DHS 157.03(155)(155) “Healing arts” means a profession concerned with diagnosis and treatment of human maladies, including the practice of medicine, dentistry, osteopathy chiropractic and podiatry. DHS 157.03(156)(156) “Healing arts screening” means the exposure of a human being to x-rays without prior examination disclosing a need for an x-ray procedure and prescription for such a study by a practitioner of the healing arts. DHS 157.03(157)(157) “Heat unit” means a unit of energy equal to 0.75 joule. It is approximately equal to the energy given by the product of the peak kilovoltage, milliampere and seconds, which is kVp x mA x time in seconds. DHS 157.03(158)(158) “Helmet” means a rigid respiratory inlet covering that also provides head protection against impact and penetration. DHS 157.03(159)(159) “High dose-rate remote afterloader” or “HDR” means a device that delivers a dose rate in excess of 12 gray (1200 rads) per hour. DHS 157.03(160)(160) “High radiation area” means an area, accessible to individuals, in which radiation levels from radiation sources external to the body could result in an individual receiving a dose equivalent in excess of one mSv (0.1 rem) in one hour at 30 centimeters from any source of radiation or 30 centimeters from any surface that the radiation penetrates. DHS 157.03(161)(161) “Hood” means a respiratory inlet covering that completely covers the head and neck and may also cover portions of the shoulders and torso. DHS 157.03(162)(162) “Human use” means the internal or external administration of radiation or radioactive material to human beings. DHS 157.03(163)(163) “Image intensifier” means a device, installed in its housing, which instantaneously converts an x-ray pattern into a corresponding light image of higher intensity. DHS 157.03(164)(164) “Image receptor support” means, for mammographic systems, that part of the system designed to support the image receptor during mammography. DHS 157.03(165)(165) “Image receptor” means any device, such as a fluorescent screen or radiographic film, which transforms incident x-ray photons either into a visible image or into another form that may be made into a visible image by further transformations. DHS 157.03(166)(166) “Independent certifying organization” means an independent organization that meets all of the criteria specified in 10 CFR 34, Appendix A. DHS 157.03(166m)(166m) “Indian Tribe” means an Indian or Alaska native tribe, band, nation, pueblo, village, or community that the Secretary of the Interior acknowledges to exist as an Indian tribe pursuant to the Federally Recognized Indian Tribe List Act of 1994, 25 U.S.C. 479a. DHS 157.03(168)(168) “Individual monitoring” means the assessment of any of the following: DHS 157.03(168)(a)(a) Dose equivalent by the use of individual monitoring devices or by the use of survey data. DHS 157.03(168)(b)(b) Committed effective dose equivalent by bioassay or by determination of the time-weighted air concentrations to which an individual has been exposed. DHS 157.03(169)(169) “Individual monitoring devices,” mean devices designed to be worn by a single individual for the assessment of dose equivalent. Examples of individual monitoring devices are film badges, thermoluminescent dosimeters, optically stimulated luminescent dosimeters, pocket dosimeters, direct reading dosimeters and personal air sampling devices. DHS 157.03(170)(170) “Industrial radiography” means an examination of the structure of materials by the nondestructive method of utilizing ionizing radiation to make radiographic images. DHS 157.03(171)(171) “Inherent filtration” means the filtration of the useful beam provided by the permanently installed components of the tube housing assembly. DHS 157.03(172)(172) “Injection tool” means a device used for controlled subsurface injection of radioactive tracer material. DHS 157.03(173)(173) “Inspection” means an official examination or observation by the department including tests, surveys and monitoring to determine compliance with rules, regulations, orders, requirements and conditions of the department. DHS 157.03(174)(174) “Interlock” means a device preventing the start or continued operation of equipment unless certain predetermined conditions prevail. DHS 157.03(175)(175) “Internal dose” means that portion of the dose equivalent received from radioactive material taken into the body. DHS 157.03(176)(176) “Ionizing radiation” means alpha particles, beta particles, gamma rays, x rays, neutrons, high-speed electrons, high-speed protons and other particles capable of producing ions. “Ionizing radiation” does not include radiowaves or microwaves, visible, infrared or ultraviolet light.