During each cycle, an amount of liquid is displaced equal to the difference in the volumes of the chambers minus the volumes of the pistons.

This process repeats itself in a continuous flow mode at the rates of 1 to 210 complete cycles per second proportionately to the fluid flow through the meter. In the FMTD4 Microflowmeter, each cycle displaces approximately .02 cc. Approximately 200,000 cycles will displace one gallon. The FMTD20 Microflowmeter has a flow rate capacity five times larger than the FMTD4.

Signal detection is accomplished by light interruptions of a photo emitter/detector device. A ferromagnetic wire tracks the magnet in the nutator [through a pressure tight barrier] causing these interruptions. The interruptions are electronically manifested as sine waves which are then conditioned by conventional electronic means to provide a square wave output.