文摘
Two methods for calculating the equivalent or effective transmittance of net liquid materials by using transmittances of optical cell were introduced, and three double-thickness transmittance methods (DTTs) to determine the optical constants of liquid materials were comparatively investigated. The transmittance spectrograms at normal incidence of optical cell with water at different thicknesses were measured in spectral range 2–2.5 μm, and the optical constants of water were calculated by three methods, which are used to validate these methods with the existing data of reference. The results show that DTTs can not accurately calculate the optical constants of liquid materials by using the equivalent or effective transmittance data of liquid materials, and DTTs using the transmittance spectrum of optical cell filled with liquid materials can effectively calculate the optical constants of liquid materials.