NAC459.586. Therapeutic X-ray systems: Beam monitor.

Equipment installed after February 28, 1980, of greater than 150 kVp must be provided with a beam monitor system as follows:

     1. It must include a transmission detector which is a full beam detector and which is placed on the patient side of any fixed added filters other than a wedge filter;

     2. It must have the detector interlocked to prevent incorrect positioning in the useful beam;

     3. It must have a display at the control panel from whose reading in dose monitor units the absorbed dose at a reference point in the treatment volume can be calculated;

     4. The control panel display must maintain the reading until intentionally reset to zero;

     5. In the event of electrical power failure the reading at the control panel display must be recoverable at a later time;

     6. Irradiation may be allowed only after a selection of a number of dose monitor units has been made at the treatment control panel;

     7. It must be capable of independently terminating irradiation when a preselected number of dose monitor units has been reached; and

     8. The control panel display must have only one scale, no scale multiplying factors, and be designed so that an increasing dose is displayed by increasing numbers and that in the event of an overdosage of radiation the absorbed dose may be accurately determined.

     [Bd. of Health, Radiation Control Reg. §§ 6.8.1.8-6.8.1.8.8, eff. 2-28-80]