Measurement of thermal diffusivity and speed of sound of dibutyl ether from 303.15 K to 688.15 K and up to 7.5 MPa

The thermal diffusivity and the speed of sound in dibutyl ether (DBE) were measured using light scattering method, including saturated liquid/vapor and supercritical region. The expanded relative uncertainty ( k  = 2) of the thermal diffusivity and the speed of sound was estimated to be less than 2% and 0.5% over the whole investigated range of states. Polynomial representations for the thermal diffusivity and the speed of sound were fitted to the data in saturated liquid/vapor. For the thermal diffusivity, the AAD is 0.50% for the saturated liquid and 0.67% for the saturated vapor . For the speed of sound, the AAD is 0.41% for the saturated liquid and 0.35% for the saturated vapor. The tendency of the thermal diffusivity and the speed of sound to temperature and pressure in supercritical region are also analyzed.