Figures & data
Figure 1. Second by second regression of ultrasonic versus CO2 tracer measurements of vehicle exhaust flow rate over the combined FTP + US06 drive cycle. The inset compares the time response of the ultrasonic flow meter to the CO2 tracer method over a 45 s portion of the US06 cycle.
Figure 2. Proportionality of sample flow rate into the PFD versus the 2.0 L GTDI vehicle exhaust flow rate for each phase of the FTP + US06 cycle.
Figure 3. The main graph displays regressions of gravimetric PM mass emissions measured via PFD versus CVS tunnel. Data from 15 tests in cell A and 18 tests in cell B are plotted separately for each phase of the FTP cycle. The inset provides an expanded view of PM emissions in the 3 mg/mi range. The lower graph displays the residuals.
Figure 4. PM mass measured by PFD, in the CVS tunnel, and soot measured photoacoustically from 17 repeat FTP tests of the 2012 GDI test vehicle at two sites. The panels show FTP weighted average (top left) and phase by phase PM emissions rates. Note the different vertical scale for the cold start data. Lines are to help distinguish test-to-test trends between the different measurement methods.
Figure 5. Single versus three filter measurements of FTP weighted average PM mass emissions.
Figure 6. US06 cycle PM mass emissions recorded via PFD versus CVS tunnel and MSS. The lines are to help distinguish test-to-test trends amongst the different measurement methods.
