Method and apparatus for measuring mass airflow
US4463601A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 23, 1983 |
| Grant date | Aug 7, 1984 |
| Priority date | — |
| Expiry date | May 23, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F1/72
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Where airflow through a system is subject to forward and reverse flow, the mass airflow rate is determined by providing two flow branches A and B meeting at a junction wherein the two branches carry different proportions of airflow in the forward and reverse directions and branch B carries a greater fraction of the airflow during reverse flow than during forward flow. An airflow sensor in each branch measures the airflow irrespective of flow direction to obtain mass flow rate signals R.sub.A and R.sub.B for branches A and B, respectively. The mass airflow rate m is calculated from the equation m=K.sub.A R.sub.A -K.sub.B R.sub.B where m, K.sub.A and K.sub.B are constants for a given apparatus which are determined by each sensor characteristic and the flow characteristics of the junction. The resultant mass flow rate signal m will have a positive or negative sign indicative of forward or reverse flow. Integrating the value m over a time period and dividing by the time period yields the average mass airflow rate for the period. This method and apparatus can be used to obtain accurate induction airflow measurements for internal combustion engines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.