A vane type airflow meter is a sensor in which measures airflow by the use of a flap which has a pre-tensioned spring on it which opens and closes depending on the amount of airflow to the intake. As the flap moves, it is connected to a contact which slides on a carbon resistor strip which changes resistance due to the vain movement. As a 5V source is applied to E2 on the diagram it passes through the resistor and through the moving slider and sends an output signal to the ECU (vs). By the movement of the slider on the carbon track it changes the resistance between the slider and the 5v supply because the contact is further away from the supply and this changes the output voltage signal to the ECU which tells the ECU how much air is passing through the airflow meter to the intake.
i hooked up a vain AFM with a 5v input and ground and measured the output as i changed the angle of the vain.
| Vane angle (degrees) | Voltage output (Volts) |
| 0 | 1.6 |
| 20 | 2.3 |
| 40 | 3 |
| 60 | 3.5 |
| 80 | 4 |
| 100 | 4.4 |
| 120 | 4.9 |
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| Graph of data from table above |
