Flow sensor response

[MethoD]

I have the Aquamist injector "input" connected directly to an ECU Auxiliary output, rather than to one of the injectors. This way I have precise control over when it starts injecting and the rate. I have the flow meter 0-5v output fed back into the ECU so I can monitor flow and adjust ECU parameters based on the value.

I can view all this activity in the ECU logs and I have noticed that there is a small bit of lag between the FAV opening and the flow detected by the flow meter. Perhaps about 1/2 second.

While I expect a bit of lag when ramping up, I have also noticed that when the FAV duty cycle is quickly shut down completely, such as when lifting off the throttle (thus no flow past the FAV), it takes that same bit of lag time for the flow meter gradually taper down to 0.

What I am wondering is -- is the behavior I am seeing because of inertia of the flow meter impeller? I assume in the case of the taper down the answer would be "yes" since the flow meter is before the FAV thus fluid flow should stop instantly.

Thanks
M