NAC459.588. Therapeutic X-ray systems: Timer; control panel.

     1. A timer must be provided which has a display at the treatment control panel. The timer must have a preset timer selector and an elapsed time indicator.

     2. The timer must be a cumulative timer which switches on and off with the radiation and retains its reading after irradiation is interrupted or terminated. It must be necessary to zero the elapsed time indicator and the preset time selector after irradiation is terminated.

     3. The timer must terminate irradiation when a preselected time has elapsed.

     4. The control panel must have:

     (a) An indication of whether electrical power is present and activation of the X-ray tube is possible;

     (b) An indication of whether X rays are being produced;

     (c) The means for indicating kilovoltage and X-ray tube current;

     (d) The means for terminating an exposure at any time;

     (e) A locking device which will prevent unauthorized use of the X-ray system; and

     (f) For new equipment installed after February 28, 1980, a positive display of specific filter or filters in the beam.

     5. When a control panel may energize more than one X-ray tube:

     (a) It must be possible to activate only one X-ray tube during any one time interval;

     (b) There must be an indication at the control panel identifying which X-ray tube is energized; and

     (c) There must be an indication at the X-ray tube housing assembly when that tubehead is energized.

     6. There must be means of determining the target to patient distance to within 1 centimeter.

     7. Unless it is possible to bring the X-ray output to the prescribed exposure parameters within 5 seconds, the entire useful beam must be attenuated by a shutter having a lead equivalency not less than that of the tube housing. In addition:

     (a) After the unit is at the selected operating parameters, the shutter must be controlled electrically by the operator from the control panel; and

     (b) An indication of shutter position must appear at the control panel.

     [Bd. of Health, Radiation Control Reg. §§ 6.8.1.9-6.8.1.13.2, eff. 2-28-80]