Measurement of the refractive index of distilled water from the near-infrared region to the ultraviolet region

Abstract

By the minimum deviation method using a prism shaped cell, the absolute refractive indices of high-performance liquid chromatography distilled water were measured at the wavelengths from 1129 to $182\text{\hspace{0.17em} nm}$, at the temperature of $\text{19 \hspace{0.17em}}°\text{C}$, $\text{21 .5 \hspace{0.17em}}°\text{C}$, and $\text{24 \hspace{0.17em}}°\text{C}$, and then dn∕dt at $\text{21 .5 \hspace{0.17em}}°\text{C}$ was calculated. The coefficients of the four-term Sellmeier dispersion formula were determined by using the refractive indices at each temperature. As a result of the comparison of our refractive index data in the visible wavelength region with the formula by Tilton et al. at the National Bureau of Standards in 1938, both the refractive index data corresponded within $\text{6}\times {\text{10}}^{-6}$. In the UV region, the absolute refractive index at $193.39\text{\hspace{0.17em} nm}$ calculated by the data measured nearby the wavelengths from 200 to $\text{190 \hspace{0.17em} nm}$ was 1.436517 $\left(\text{21 .5 \hspace{0.17em}}°\text{C}\right)$. The value was lower by $9\times {10}^{-5}$ or $10\times {10}^{-5}$ than the data measured by Burnett et al. at the National Institute of Standards and Technology.