Abstract: The invention measures the flow of a liquid by measuring the effect of that flow on a laser beam which travels from a laser source, through the flow, and landing upon a detector oriented to receive that laser source. Interfaces within the flow stream will refract the laser beam and cause variations in strength of the energy reaching the detector. These variations in the forward scatter occur at audio and super audio frequencies. The flow rate is proportional to audio frequency which can be measured and correlated by comparison to known flow rates.