1. (1) The protective tube housing shall be of diagnostic type.
2. (2) Collimating devices capable of restricting the useful beam to the area of clinical interest shall be used and shall provide the same degree of protection as is required of the tube housing.
3. (3) The X-ray films used as the recording medium during the X-ray examination shall show substantial evidence of cut-off (beam delineation).

4. (4) The aluminum equivalent of the total filtration in the useful beam shall not be less than that shown below:

   Operating kVp	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

5. (5) A device shall be provided which terminates the exposure after a preset time interval or exposure. The exposure switch shall be of the dead-man type and where protective barriers are required shall be so arranged that it cannot be operated outside the shielded area.

6. (6) Each installation shall be arranged so that the operator can stand at least six feet from the patients, the X-ray tube and the useful beam during exposure. A protective barrier shall be provided when the operator cannot stand at least six feet away from the patient, the X-ray tube and useful beam during exposures.

   (b) Conditions for operation of equipment.

7. (1) No person shall hold film during the exposure.
8. (2) Only persons required for the radiographic procedure shall be in the radiographic room during exposure.

(a) Equipment.