SIGNAL PROCESSING METHOD AND APPARATUS FOR FLOWMETERS

摘要

A flagpole type of flow barrier is inserted in a pipeline. High pressure swirling vortices or eddies flow downstream from the flagpole barrier. The quantity of vortices per unit time is sensed by a small wing placed downstream in the flagpole barrier wake. The wing movements cause electronic pulses. Many other forces in the pipeline including pipe vibrations and flow anomalies also cause the wing to move thereby creating additional electric pulses known as noise pulses. The combined signals of the vortice pulses and the noise pulses are transmitted into an electronic computer processor. The electronic computer processor amplifies and processes the incoming pulses. Fourier analysis (1.4-1.7) and cross-correlation (2.2) techniques are used to eliminate the noise pulses from the incoming vortex pulses (1.3). The true vortex count per unit time or frequency is isolated from the noise pulses. The true vortex frequency is then used to calculate the fluid flow through the pipeline.