The QA procedures are a control loop composed of two functions: Assessment of data quality by measurement of COM performance; and Control and improvement of data quality by implementing QC policies and corrective actions. When the assessment function indicates that data quality is inadequate, the control effort shall be increased until data quality is acceptable. COM Accuracy Determination. Quarterly performance audits involving a series of checks of monitoring system components and operation shall be performed to assess the accuracy of the COM data. Calibrated audit materials shall be required for certain checks as specified by this chapter. The opacity monitoring data shall be considered accurate if the required audits do not identify problems that detract from the accuracy of the COM data. Quality control and corrective actions encompass a variety of policies, specifications, standards, and corrective measures. To accommodate these site-specific variables, this chapter treats QC requirements in general terms to allow each source owner or operator to develop a QC system that is more effective and efficient for the circumstances. However, the final data output device used to report emissions to the Department in the quarterly excess emissions report shall be used for all required QA and QC measurements.