Abstract: A fluid flowmeter, of a type including a housing and a fluid flow measurement assembly rotatable therein which is driven by a turbine, is described in detail to illustrate a limitation on low flow rate operational capability and a related problem of contaminant particle malfunctions. A specific flowmeter used for such illustration is a typical prior art motorless mass flowmeter including a turbine secured to and rotatable with a shaft which in turn rotates a downstream impeller by means of a spring, the impeller being independently supported for rotation, so that relative deflection between the impeller and the shaft is a measure of mass flow rate.