On older vehicles, it was common to use Vane (Volume) Air Flow (VAF) sensors. It is just a vane attached to a potentiometer. Reading the position of the pot, we know the position of the vane, and from the geometry of the sensor, the amount of air going to the engine.
On some VAF sensors, the potentiometer, has a weird "geometry". It uses several trimmed resistors. The resistor between the wiper and a terminal will give a resistance that fluctuates from a value (that will rise with the position of the wiper) and a fixed low value (diagram bellow).
Is there a advantage to do so?
Alexander.