CVS-7000 - Constant Volume Sampler

Light-Duty Gasoline/ Alternative Fuels Testing Exhaust flows into the mixing tee where it is diluted with ambient air to prevent water condensation. Sample of ambient air is sent to the Bag Sampling Unit for storage in bags. From the mixing tee, diluted exhaust sample enters the Exhaust Sampling Unit, which measures dilute-exhaust flow rate and volume. Sample of the dilute exhaust - extracted proportionally before the critical flow venturi - proceeds to the Bag Sampling Unit for storage in sample bags. Emission analyzers measure concentrations of THC, CO, CO2, NOx, and CH4 in bags. The mass of HC, CO, NOx, CO2, CH4 is calculated from Gas Concentration in the Bag, Gas Density, and Total CVS Volume.