A capacitance measurement system for vertical upward gas-liquid two-phase flow has been established to explore the feasibility for measuring fluid phase-concentration by using concave capacitance sensor and double helix capacitance sensor. The experimental results prove that the concave capacitance sensor has poor measurement resolution

but double helix capacitance sensor shows high resolution in phase-concentration measurement. The fluctuation signals of the two types of capacitance sensors are analyzed by means of time frequency analysis. The time frequency representation can effectively identify flow patterns and characterize their motion clearly. Finally

the drift model of gas-liquid two-phase flow is employed based on the measurement signals of double helix capacitance sensor. Moreover

the phase superficial velocities are estimated for slug and churn flow patterns

and good prediction results are achieved. The results show that the double helix capacitance sensor possesses a good application prospect for measuring the flow parameter in gas-liquid two-phase flows.