R 333.5405 X-ray equipment.

Rule 405. (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 the values shown in table 405. TABLE 405 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) 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. (4) Beam-limiting devices shall be calibrated in terms of the size of the projected useful beam at specified source-image receptor distances (SID). This calibration shall be clearly and permanently recorded on the beam-limiting device. Calibration of adjustable beam-limiting devices shall permit reproducible settings. (5) 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 not 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. (6) General purpose radiographic x-ray systems should be equipped with adjustable beam-limiting devices containing light localizers that define the entire field. (7) 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. (8) 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 beam-limiting devices shall provide the same precision. (9) 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. (10) A device shall be provided which terminates the exposure at a preset time interval or exposure limit. The operator shall be able to terminate the exposure at all times by discontinuing pressure upon the exposure switch except that during serial radiography means may be provided to permit completion of a single exposure of the series in progress. (11) A primary radiographic exposure switch shall be provided which shall be securely fixed so that the operator shall be behind a fixed shield which intercepts the useful beam and radiation which has been scattered only once. (12) An auxiliary foot switch may be provided to activate the radiographic tube in addition to, but not in substitution of, the requirement of subrule (11) of this rule. This auxiliary switch need not be fastened behind a fixed shield. (13) The control panel shall provide positive visual identification of the production of x-rays when the x-ray tube is energized. A milliammeter may meet the requirement of this subrule. (14) A signal audible to the operator shall indicate that the exposure has ended. (15) 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.