R 333.5362 X-ray equipment.

Rule 362. (1) All x-ray tube housings in fixed radiographic installations shall be of the diagnostic type. (2) The aluminum equivalent of the total filtration in the useful beam shall not be less than that shown in table 362. TABLE 362 Operating Potential Minimum Total Filter (Inherent plus added) Below 50 kVp 0.5 mm aluminum 50-70 kVp 1.5 mm aluminum Above 70 kVp 2.5 mm aluminum (3) If the filter in the machine is not accessible for examination and the total filtration is not known, subrule (2) of this rule may be assumed to have been met if the half-value layer is not less than any of the following: (a) 0.6 mm aluminum at 49 kVp. (b) 1.6 mm aluminum at 70 kVp. (c) 2.6 mm aluminum at 90 kVp. (4) Under conditions of subrule (3) of this rule, for tube potentials above 90 kVp, subrule (2) of this rule may be assumed to have been met if the half-value layer is not less than that specified in table 325-2 in R 333.5325(5). (5) Beam-limiting devices, such as diaphragms, cones, or adjustable collimators, capable of restricting the useful beam to the area radiographically recorded shall be provided to define the beam and shall provide the same degree of attenuation as that required of the tube housing. (6) Beam-limiting devices shall be calibrated in terms of the size of the projected useful beam at specified source-image receptor distances (SID). The calibration shall be clearly and permanently recorded on the beam-limiting device. Calibration of adjustable beam-limiting devices shall permit reproducible settings. (7) X-ray systems designed for only 1 image receptor size at a fixed SID shall be provided with means to limit the field at the plane of the image receptor to dimensions no greater than those of the image receptor, and to align the center of the x-ray field with the center of the image receptor to within 2% of the SID. (8) The size of the x-ray beam projected by fixed aperture beam-limiting devices, except those used for stereoradiography, shall not exceed the dimensions of the image receptor by more than 2% of the SID when the axis of the x-ray beam is perpendicular to the plane of the image receptor. (9) The calibrated field size indicator on adjustable beam-limiting devices shall be accurate to within 2% of the SID. The light field shall be aligned with the x-ray field with the same degree of accuracy. The field size projected by automatic adjustable collimators shall provide the same precision. (10) For radiographic procedures resulting in multiple views on a single image receptor, the beam-limiting device shall limit the x-ray field size to the recorded radiographic image size within 2% of the SID. Covering a portion of the image receptor with radio-opaque material is not a substitute for proper x-ray field limitation. (11) A device shall be provided to terminate the exposure at a preset time interval or exposure limit. The operator shall be able to terminate the exposure at any time by discontinuing pressure upon the exposure switch. (12) Unless protective shielding is provided for the operator, the length of the exposure control switch cord or remote control location shall be such that the operator shall be able to stand at least 1.8 meters (6 feet) away from the patient and the x-ray tube and out of the useful beam. When protective shielding is provided, the operator shall always be entirely behind the shield during the exposure. (13) The control panel shall provide positive identification of the production of x-rays when the x-ray tube is energized. A milliammeter may meet the requirements of this subrule. (14) The technique factors to be used during an exposure shall be indicated before the exposure begins. When automatic exposure controls are used, only those technique factors which are set before the exposure shall be indicated. On equipment having fixed technique factors, this requirement may be met by permanent markings. Indication of technique factors shall be visible from the operator's position. (15) A signal audible to the operator shall indicate that the exposure has ended.