Gas flow measuring apparatus

摘要

An intake barrel connected to an intake pipe of an internal combustion engine is provided therein with a venturi member. Openings are formed in the wall of the intake barrel at the upstream and downstream sides of the venturi member. A bypass passage forming member provided with a groove of a length greater than the distance between said openings is fixed to the outside of the intake barrel. A bypass passage is formed by these openings and the groove. A spacer is interposed between the intake barrel and the bypass passage forming member. The cross-sectional area of the bypass passage can be varied by varying the thickness of the spacer.