Sensor - Vane AFM

The Vane AFM means Vane Air Flow Meter show as below

Test vane angle and voltage out

When vane angle is 0 degree

When vane angle is 30 degree

When vane angle is 45 degree

When vane angle is 75 degree When vane angle is 90 degree

Vane Angle and Voltage Out

Vane Angle	Voltage Out
0	3.81V
30	2.41V
45	1.37V
75	0.8V
90	0.35V

The graph

The specification of the AFM

  My results are within the manufacture's specifications. When the measuring plate opening, the voltage output increase.

Explain internal operation and why your voltage changes.

The circuit of it show as below

When the opening angle of the measuring plate changes, the resistance of Vs-Vb changes. E2 is ground,so the available voltage of Vs as the voltage output signal changes. Opening angle increased, rssistance between Vs and E2 increase, so voltage output increased.