If the facility’s medical physicist provides the facility with documentation that the FFDM units and accessory components are matched (see below), then the facility may perform its periodic QC tests using any review workstation or laser printer, as long as each accessory component is tested at its recommended frequency. For example, if the QC manual specifies performing the phantom image test on a weekly basis, the facility may produce a phantom image using each of its x-ray units and evaluate them on any review workstation or laser printer at least once each week of use. One mechanism by which the medical physicist can consider the FFDM units and the accessory components to be matched is for the medical physicist to initially perform and obtain passing results for all applicable QC tests through all possible combinations. (In this scenario each accessory component must be operating within its own pre-established action limits set forth in the applicable QC manual.) 21 CFR 900.12(e)(6). This method will reduce the number of QC tests that must be performed. Note: At least one example of each required QC test must be evaluated using each accessory component at the required periodic frequency. 21 CFR 900.12(e)(6).