Table II - Filtration Required vs. Operating Voltage

Total Filtration (inherent plus added)

F.                 Exposure reproducibility. The coefficient of variation shall not exceed 0.10 when all technique factors are held constant. This requirement is satisfied if the value of the average exposure

(E)   is greater than or equal to five times the difference between the maximum exposure (Emax) and minimum exposure (Emin) when four exposures are made at identical technique factors, [E ³ 5(Emax - Emin)].

G.               Accuracy  deviation.  A   registrant  shall  not  use  an  x-ray

Operating Voltage (kVp)

(millimeters aluminum

equivalent)

machine if the measured technique factors for kVp and time duration are not within the limits specified by the manufac-

Below 51                                  0.5 millimeters

51 - 70                                      1.5 millimeters

Above 70                                 2.5 millimeters

3.        The registrant shall use beryllium window tubes that have a minimum of 0.5 millimeters aluminum equivalent fil- tration permanently mounted in the useful beam.

4.        For capacitor energy storage equipment, the Agency shall determine compliance with the maximum quantity of charge per exposure.

5.        When determining the minimum aluminum equivalent filtration, the registrant shall include the filtration con- tributed by all materials that are always present between the focal spot of the tube and the patient (for example, a tabletop when the tube is mounted “under the table” and inherent filtration of the tube).

D.      Multiple tubes. If two or more radiographic tubes are con- trolled by one exposure switch, the operator shall clearly indi- cate which tube or tubes have been selected before initiation of the exposure, activating one light on the x-ray control panel and a second light at or near the tube housing assembly, each indicating the tube or tubes that have been selected.

E.       Mechanical support of tube head. The registrant shall adjust the tube housing assembly supports so that the tube housing assembly will remain stable during an exposure, unless the tube housing movement is a designed function of the x-ray system.

turer. In the absence of the manufacturer’s specifications, a registrant shall not use an x-ray machine if the measured kVp is not within 10 percent of the indicated kVp value and the measured time duration is not within 20 percent of the indi- cated time.

Historical Note

Adopted effective June 30, 1977 (Supp. 77-3). Amended subsections (A) and (B) effective August 8, 1986 (Supp. 86-4). Amended effective January 2, 1996 (Supp. 96-1).

Amended effective June 13, 1997 (Supp. 97-2). Amended by final rulemaking at 9 A.A.R. 4302, effective Novem- ber 14, 2003 (Supp. 03-3). Amended by final rulemaking

at 15 A.A.R. 1023, effective August 1, 2009 (Supp. 09-2). Amended by final rulemaking at 19 A.A.R. 3882, effec- tive January 4, 2014 (Supp. 13-4).