Abstract: A system for determining fluid flow characteristics and relaying the information to the surface. The system is ideal for use in horizontal or deviated wellbores since orientation of the wellbore with respect to the vertical will not appreciably affect the system's operation. In the described embodiment, a fluid-driven siren flowmeter is placed within a production string downstream of the location of a completion zone, the flowmeter relays representative information downstream via a fluid column to a signal detection assembly. The flowmeter includes a stationary stator, a rotatable rotor and a turbine deflector which is positioned upstream of the rotor and angularly directs the flow of passing fluid to rotate the rotor. In the case of multiple completed zones described, multiple flowmeters are sequentially mounted along the same production string, each providing signals of different characteristics.