At the University of Liverpool we have developed a real-time, non-intrusive multiphase dielectric meter capable of measuring the dielectric properties of different mixtures of oil, gas and water in full well stream flow. The design of such a microwave cavity using a range of rf and microwave is described. The experimental results with a wide range of multiphase mixtures from 0 to 100% are reported. In this paper we also present the implementation of a neural network to simulate the response of the meter under all conceivable conditions. Other parameters including pump speed, temperature, salt and sand are also discussed.