of Method 20.

6.3 Measurement System Preparation, Analy: Calibration Error. and Sampling System Bias Check. Follow Sections 6.2 through 6.4 of Method 6C. 7. Emission Test Procedure. 7.1 Selection of Sampling Site and Sampling Points. Select 8 measurement site and sampling points using the same criteria that are applicable to tests performed using Method 3. 7.2 Sample Collection. Position the sampling probe at the first measurement point. and begin sampling at the same rate as used during the sampling system bias check. Maintain constant rate sampling (i.e., +10 percent) during the entire run. The sampling time per run shall be the same as for tests conducted using Method 3 plus twice the system response time. For each run, use only those measurements obtained after twice the response time of the measurement system has elapsed to determine the average effluent concentration. 7.3 Zero and Calibration Drift Test. Follow Section 7.4 of Method 6C. 8. Quality Control Procedures. The following quality control procedures are recommended when the results of this method are used for an emission rate correction factor. or excess air determination. The tester should select one of the following options for validating measurement results: 8.1 If both O₂ and CO₂ are measured using Method 3A. the procedures described in