Abstract: A transducer for measuring gravital fluid flow includes a composite weir member having a downstream Palmer-Bowlus flume section and an upstream uniform channel section. A flexible sealed envelope partially filled with dielectric fluid is disposed in the bottom of the uniform channel, and is in open flow communication with a sealed vertical column secured to the channel wall. A pair of capacitive probe electrodes are disposed within the column and the envelope. Fluid pressure of the liquid flowing in the weir forces the dielectric fluid up into the column, thereby altering the capacitive coupling of the electrodes in a manner which is a direct function of the amount of fluid flow in the weir.