Exhaust gas flow measurement device

摘要

An internal combustion engine exhaust emission control system has a module for conveying exhaust gas from an engine exhaust system to an engine intake system. A valve selectively restricts the flow path. A pressure sensing passage communicates a pressure sensing port of a pressure sensor to the flow path. The pressure sensing passage comprises a tube having an end portion passing through a through-hole in a side wall of the flow path. In one embodiment, an open free end of the tube is disposed within the flow path in spaced relation to the side wall opposite an orifice that creates a pressure drop for obtaining a flow measurement using pressure sensed via the tube as one input. In another embodiment, the open free end of the tube is disposed flush with the side wall opposite a nozzle.