Abstract: An emission testing system particularly suited for vehicle emission testing. The system includes at least one research grade non-dispersive infrared (NDIR) unit, a chemiluminescence detector (CLD) unit and a flame ionization detection (FID) unit. All of the analytical units are incorporated in the system for operation with a sample which has been subjected to a single conditioning step. In this manner each analytical unit tests a uniformly conditioned sample. The system is capable of sampling both raw emissions for raw emission idle tests (BAR 90) and dilute volume samples for dilute volume sample mass emission tests under IM-240 regulations.

Abstract: A zero air generating system comprises a hydrocarbon and NO oxidizer and a molecular sieve unit which are interconnected by suitable lines for continuous processing of the air stream. Flow control means is provided to maintain the flow rate of the air being treated to 5 liters/minute or less. The system may also include a separate NO to NO.sub.2 converter. The system purifies shop air by reducing the concentration of contaminants such as NO.sub.2, CO, CO.sub.2, H.sub.2 O and other remaining unoxidized hydrocarbons to levels acceptable under the IM-240 specification for instrument air. In a preferred embodiment of the invention, two parallel connected molecular sieves units are utilized in the system. Thus the air being treated can alternately flow through one molecular sieve while the other unit is in the process of being regenerated.

Abstract: There is provided an emission testing system which maintains system integrity and which can be manufactured at less cost than current standard emission testing systems. The system includes a sampling unit for collecting emissions from a vehicle and diluting the collected emissions with background ambient air as required and means for drawing a proportional test sample from the bulk air/emission mixture. The analyzer is a single unit which includes a reaction cell for chemiluminescence reactions and a combustion cell for flame ionization analysis. In addition the system includes a common sample conditioning for the test sample prior to splitting the test sample for chemiluminescence and flame ionization analysis.