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, M o (integrated intensities), and simple peak‐height determinations under isothermal conditions (323 K) over a pressure range of 20–2400 bar in a mixture of CH 4 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 ν 1 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.