借助自行研制并经改进的多点电导传感器和微机化实时在线测量系统，对垂直管外自由降膜流表面波的演化进行实时在线测量。结果表明，表面波的演化具有显著的非线性特性，其波形不仅与纵向距离和时间有关，而且还与液膜雷诺数有极大关系；此外，表面波的形态及其演化还对初始扰动比较敏感。根据测量结果估算了与数值模拟有关的波速。 With the self-developed and improved multi-point conductivity sensor and the computerized real-time on-line measurement system, the on-line real-time on-line measurement of the free falling film flow surface wave outside the vertical tube was measured. The results show that the evolution of surface wave has significant nonlinear characteristics. The waveform is not only related to the longitudinal distance and time, but also has a great relationship with the Reynolds number of the liquid film. In addition, the shape and evolution of the surface wave also compare with the initial disturbance sensitive. Based on the measurement results, the wave velocity related to the numerical simulation was estimated.