Abstract: Babin model is an advanced method of evaporation waveguide diagnosis, to improve the effect of this model, the formulas is deduced , and the sensitivity of its inputting parameters is analysed with the method of simulation, the research shows that the relative humidity is the most sensitive parameter in condition of unstable atmospheric layer, and surface temperature is the most sensitive parameter in condition of stable and neutral atmospheric layer, and the turbulence of air pressure is almost no effect on the calculation result. High precision sensors of relative humidity and surface temperature should be selected when evaporation vaveguide is diagnosed from the parameters measured above the surface.

Key words: Evaporation, Waveguide, Babin model, Measurement error