Spectrophone Measurements of Water Vapor Absorption Coefficients

It is well known that the experimental water vapor absorption coefficients are larger than those generated by theoretical methods [1]. This is readily _, apparent in the region less than 100 cm where calculations using standard line-shapes differ from experimental data by factors of 2, 3 or larger. Explanations for this include incorrect lineshape functions, the presence of dimers or water clusters, or a combined effect due to several causes. Our purpose in doing this experiment has been to generate a large data base including absorption coefficients at several frequencies and for many different combinations of water vapor and total pressure. Hopefully, this data will provide sufficient information in order to generate a more accurate water vapor absorption model and understand the cause of the difference in the experimental and theoretical values.