A method for measuring exhaust gas recirculation flow

摘要

A method for measuring exhaust gas recirculation flow in an engine 102 is provided. The method comprises separating EGR flow into a first flow and a larger second flow, passing the separated first flow through a restriction region 208 having an orifice plate 210 so that the first flow can be measured while it is separate from the second flow and combining the separated second flow with the first flow and inducting the combined flows into a cylinder of the engine 102. The invention allows a more accurate measurement to be made by using a smaller diameter orifice plate without introducing excessive flow restriction.