Yup, you mean one slot aperture is wider, so the processor would know
when the larger cup is crossing the sensor... works. The longer pulse
means home position, the shorter period between pulses would say when
the big cup is facing the wind. The angular position between them would
tell the wind angle related to the sensor physical position.

"Paul B. Webster VK2BZC" wrote:
>
> Wagner Lipnharski wrote:
>
> > If you install another sensor (one pulse per revolution) in the
> > rotator that identify a know position (home position),
>
>   No, you only need one sensor.  The "chopper" blade is longer for one
> of the cups so the processor can figure out which cup is which.
> --
>   Cheers,
>         Paul B.