Two-sensor droplet-capable conductivity probe for measurement in liquid dispersed flows

•A novel probe is developed for local measurement in liquid dispersed flows.•Locl measurements in churn-turbulent to annular transition region are performed.•The probe’s capability in measuring gas-dispersed flows is demonstrated. In churn to annular transition, the liquid could exist as a dispersed phase (droplets). But the conventional probe is not able to distinguish the dispersed liquid phase from the gas phase due to electrode design. To extend the measurement capability of the conductivity probe, the Two-Sensor Droplet-Capable Conductivity Probe (DCCP-2) is developed, which incorporates one more sensor to distinguish the dispersed liquid phase from the gas phase and the continuous liquid phase. This paper presents the design of DCCP-2, such as the circuit design, signal processing, and probe manufacturing process. Its capability in measuring liquid-dispersed flow is demonstrated by experiments in churn to annular transition conditions. Also, it still preserves the capability of measuring bubbly flow, which is demonstrated through benchmark experiments with the conventional probe. Therefore, the DCCP-2 serves as a reliable measurement instrument covering a wide range of two-phase flow regimes from bubbly flow to annular flow.