THERMAL RELAXATION IN NITROGEN WITH WET CARBON DIOXIDE AS IMPURITY

The pressurized Kundt's tube developed in this laboratory has been used to measure the napier (relaxation) frequency of nitrogen in both binary and ternary mixtures with carbon dioxide and water vapor. Carried out at about 175°C, where the relaxing specific heat of nitrogen becomes readily measurable, the separate contaminants shift the napier frequency upward by amounts proprotional to their respective mole fractions: water vapor by 310 Hz/mole percent, carbon dioxide by 300 Hz/mole percent. When both are present, the shift is notably greater and is not linear in the mole fraction. This synergistic effect is explicable on theoretical grounds. Preliminary results with heavy water vapor (D2O) as impurity are also given. Its effect is also nonlinear in the mixed impurities. © 1969, Acoustical Society of America. All rights reserved.