Isothermal Raman depolarization ratios of supracritical carbon monoxide at pressures between 20 and 2400 bar

The Raman depolarization ratios of carbon monoxide were measured via the zeroth spectral moment, Mo (integrated intensities), and simple peak‐height determinations under isothermal conditions (323 K) over a pressure range of 20–2400 bar in a mixture of CH4 and CO. These conditions correspond to densities ranging from 0.75 to 24 mol I−1. The measurements were carried out so that the depolarization ratios being measured in other experiments from the ν1 totally symmetric stretching mode of supracritical methane could be corrected for instrumental depolarization effects. The values near a pressure of 1 bar have been calculated and measured for CO by several sets of workers. The cell windows were float glass and as a result they are known to contribute much less than quartz to depolarization. Float glass windows cause only a 0.5% error in scrambling uncertainty of the polarized light exiting the high‐pressure cell.