General Requirements for all Diagnostic X-Ray Systems

General Requirements for all Diagnostic X-Ray Systems. In addition to other requirements of this section, all diagnostic x-ray systems shall meet the following requirements: 1. Warning Label. The control panel containing the main power switch shall bear the warning statement, legible and accessible to view: "WARNING: This x-ray unit may be dangerous to patient and operator unless safe exposure factors and operating instructions are observed." 2. Battery Charge Indicator. On battery-powered x-ray generators, visual means shall be provided on the control panel to indicate whether the battery is in a state of charge adequate for proper operation. 3. Leakage Radiation from the Diagnostic Source Assembly. The leakage radiation from the diagnostic source assembly measured at a distance of 1 meter in any direction from the source shall not exceed 100 milliroentgens (25.8 µC/kg) in 1 hour when the x-ray tube is operated at its leakage technique factors. Compliance shall be determined by measurements averaged over an area of 100 square centimeters with no linear dimension greater than 20 centimeters. If leakage technique factors cannot be set on the control panel, then compliance shall be determined by measuring leakage at maximum kVp and an appropriate mAs. 4. Radiation from Components Other Than the Diagnostic Source Assembly. The radiation emitted by a component other than the diagnostic source assembly shall not exceed 2 milliroentgens (0.516 µC/kg) in 1 hour at 5 centimeters from any accessible surface of the component when it is operated in an assembled x-ray system under any conditions for which it was designed. Compliance shall be determined by measurements averaged over an area of 100 square centimeters with no linear dimension greater than 20 centimeters. 5. Beam Quality. a. Half-value Layer. i. The half-value layer of the useful beam for a given x-ray tube potential shall not be less than the values shown in Table I. If it is necessary to determine such half-value layer at an x-ray tube potential which is not listed in Table I, linear interpolation or extrapolation may be made. TABLE I X-ray tube voltage (kilovolt peak) Minimum HVL (mm of Al) Designed Operating Range Measured Operating Potential Dental Systems Medical X-ray Systems Manufactured before 06/10/2006 Medical X-ray Systems Manufactured after 06/10/2006 Below 50 1.5 0.3 0.3 1.5 0.4 0.4 1.5 0.5 0.5 50 to 70 1.5 1.3 1.3 1.5 1.5 1.5 1.5 2.1 1.8 Above 70 2.1 2.1 2.5 2.3 2.3 2.9 2.5 2.5 3.2 2.7 2.7 3.6 3.0 3.0 3.9 3.2 3.2 4.3 3.5 3.5 4.7 3.8 3.8 5.0 4.1 4.1 5.4 ii. For capacitor energy storage equipment, compliance with the requirements of 1.6.4(5) shall be determined with the maximum quantity of charge per exposure. This will be deemed to have been met if a mAs of 5-10 has been used. iii. The required minimal half-value-layer of the useful beam shall include the filtration contributed by all materials which are permanently between the source and the patient. b. Filtration Controls. For x-ray systems which have variable kVp and variable filtration for the useful beam, a device shall link the kVp selector with the filter(s) and shall prevent an exposure unless the minimum amount of filtration necessary to produce the HVL required by 1.6.4(5)(a) is in the useful beam for the given kVp which has been selected. 6. Multiple Tubes. Where two or more radiographic tubes are controlled by one exposure switch, the tube or tubes which have been selected shall be clearly indicated prior to initiation of the exposure. This indication shall be both on the x-ray control panel and at or near the tube housing assembly which has been selected. 7. Mechanical Support of Tube Head. The tube housing assembly supports shall be adjusted such that the tube housing assembly will remain stable during an exposure unless tube housing movement is a designed function of the x-ray system. 8. Technique Indicators. a. The technique factors to be used during an exposure shall be indicated before the exposure begins. If automatic exposure controls are used, the technique factors which are set prior to the exposure shall be indicated. b. The requirements of 1.6.4(8)(a) may be met by permanent markings on equipment having fixed technique factors. Indication of technique factors shall be visible from the operator's position except in the case of spot films made by the fluoroscopist. 9. Locks. All position locking, holding, and centering devices on x-ray system components shall function as intended.