The first paper by the author presented in detail the design characteristics of the pitot-venturi flow element and how they are influenced by air flow. Tests clearly show that liquid-flow performance cannot be predicted from air-flow runs and, instead, actual liquid-flow conditions are required to establish a dependable relationship between velocity and differential produced. The test setup and the instrumentation needs are described. Four-inch and six-inch pipe were used and the performance curves for these are discussed. Flow equations are included and a brief analysis of them is given.