Hey
@BrunDog, please forgive me for a dumb question. I don't know much about any of this stuff, so I feel silly questioning someone with 1000 times the knowledge I have, but...
Since the ifm outputs the signal at 4-20ma, which we will be converting to 1-5v for the arduino, isn't this going to be treated more like a pressure sensor than a pulse count flow meter. Therefore, the pulse count per second isn't an issue as you're not counting the pulses but rather converting the signal voltage to some flow rate on a scale between 0 and 6.6gpm (or whatever the max flow rate is on the meter)? If that's the case, I'd assume that having the input pulsed at 25 times per minute at 1 quart/minute sparge is more than enough (I think I saw in their literature that it pulses up to 100 times per gallon), and I'd assume that we'd probably be smoothing that somehow anyway.
I pulled the trigger on two of them, so the point is moot, but they will work well for me as I transition to an automated setup. During my transition, I'll try using the display on those meters to match my flow rates manually. If they end up working for the final build, even better.
edited to correct a math error...