Air Flow Meter/Sensor: Description and Operation

Mass Air Flow Meter





PURPOSE
The Mass Air Flow Meter measures the amount of air entering the engine. Rather than measuring air volume as displacement, the sensor measures air density. By measuring the density of the air entering the engine, compensation is made for altitude as well as temperature.

Mass Air Flow (MAF) Sensor Operation:

OPERATION
The sensor works on the principal that when the heated platinum wire is positioned within the air intake, the air volume can be measured by monitoring changes in hot wire temperature. The temperature change is measured by the thermistor. Circuit feedback maintains the platinum wire at a set temperature by controlling current flow through the circuit. The current flow is measured by the Engine Control Module as output voltage.