CRITICAL FLOW VENTURI

摘要

An apparatus for determining the total mass of exhaust gas constituents emitted from an internal or external combustion engine, the apparatus having a through-flow duct to receive the exhaust gases and into which is introduced dilution air for thorough mixing with the exhaust gases. The apparatus has means for measuring not only the total mixed flow but also the total flow of dilution air introduced to the duct. Unique means is utilized for extracting and measuring a proportional sample of said mixed flow. Collection and measuring apparatus is used to determine the concentration of dilution air constituents as well as the combined concentration of gaseous constituents in the mixed flow. Utilizing the above two flow measurements and the two constituent concentration measurements, the total mass of exhaust gas from the engine is simply determined on a theoretically correct basis.