When I finished building my flowbench and loaded the info on my laptop you go into calibration and (choose your plate size) I started at 300cfm. after it’s in place start the flowbench. If by chance it was 298-301 you lucked out. If not you go to the configure screen and raise or lower your number to dial it in. Then I checked my 100 plate and it was dead nuts on. So now you write that config number down so your have it for the future. Then you switch over to exhaust and do the same thing and write down that configuration number because it will be different. That number has the be switched (takes 45 seconds) when going from exhaust and intake. Now if you have a pilot style flowbench with fluid manometers calibration will change with the weather, mine won’t and is why I built it after having both style benches before.
