Carburettor inlet air flow measurement - using damped air float and screw driven indicator for independence from ambient pressure

摘要

An air volumetric flow measurement device for a carburettor has a continuously variable aperture in the air inlet connected to an external indicator. An air float in the measurement tube moves with the air flow through the tube the motion being damped by the choke element connected to the measurement tube outflow. The choke element has an annular aperture similar to the aperture between the air float and the measuring tube, and consists of an axially moving conical part (36) and a fixed cone (38). The device permits constant airflow to be supplied independent of ambient air pressure and indicated w.r.t. calibration marks on the external indicator, which consists of a scaled knob turned by a worm screw driven by the axially moving conical part (36).