Sensor Mass Air Flow MAF

A accumulation air breeze sensor is acclimated to acquisition out the accumulation of air entering a fuel-injected centralized agitation engine. The air accumulation advice is all-important for the agent ascendancy assemblage (ECU) to antithesis and bear the actual ammunition accumulation to the engine. Air changes its body as it expands and affairs with temperature and pressure. In automotive applications, air body varies with the ambient temperature, distance and use of a turbocharger and this is an ideal appliance for a accumulation sensor. (See stoichiometry and ideal gas law.)

There are two accepted types of accumulation airflow sensors in use on automotive engines. These are the vane beat and the hot wire. Neither architecture employs technology that measures air accumulation directly. However, with an added sensor or two, the engine's air accumulation breeze amount can be accurately determined.

Both approaches are acclimated about alone on cyberbanking ammunition bang (EFI) engines. Both sensor designs achievement a 0.0- 5.0 volt or a pulse-width accentuation (PWM) arresting that is proportional to the air accumulation breeze rate, and both sensors accept an assimilation air temperature (IAT) sensor congenital into their housings.

When a MAF is acclimated in affiliation with an oxygen sensor, the engine's air/fuel arrangement can be controlled actual accurately. The MAF sensor provides the open-loop predicted air breeze advice (the abstinent air flow) to the ECU, and the oxygen sensor provides closed-loop acknowledgment in adjustment to accomplish accessory corrections to the predicted air mass. Also see MAP sensor.