Abstract: A fluid flow device having a vortex generator in one or more channels, each channel having a converging/diverging section to scale the flow velocity to a desirable range of Reynolds number and vortex shedding frequency. Said flow device may be used as a flow meter by measuring the vortex shedding/passing frequency from each vortex generator. Further improvement is had by selecting the highest usable frequency, with its corresponding scaling factor, as the most-precise and fastest-response measurement output of the flow-measuring device. Still further improvement is gotten by cross-checking all usable frequencies against each other to detect failure of one or more vortex shedding/passing sensors.