| 摘要 |
Improvements in a mass air flow meter for inter- nal combustion engines are disclosed which comprise stntcture for improving the flow dynamics of the air flow through the sampling path including expansion of the dynamic range and increase of the signal to noise ratio resulting in improved engine performance, fuel efficien- cy, and emission control. Such structure includes a sam- ple tube (12) being tapered in decreasing area in the di- rection of air flow therethrough and a pneumatic equiva- lent of a low pass RC filter which decouples the high turbulence in the main flow through the venturi (10), av- erages same and provides a scaled down profiled flow through the sample tube for measurement by a transdu- cer (13) in the sample tube, the measurements having an accuracy of ~ 2 % of reading.
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