Must the medical physicist test the AEC in the magnification configuration, even though the unit won’t be used in that configuration by that facility?
No. The intent of the regulation is to ensure that the AEC mode is operable in all equipment configurations used clinically by the facility. The term "operable," means the AEC must meet the performance requirements of 900.12(e)(5)(i) within the 2 to 6 cm range. One way is to have the AEC tested in all the configurations provided by the system. An alternative method is to ensure that the facility does not clinically use the AEC in those configurations not previously tested by the medical physicist. This can be accomplished by placing a label on the unit’s control panel listing the configurations that cannot be used because they were not tested. These non-operational configurations must also be identified in the facility’s quality assurance records.