Thermodynamic and acoustic properties of binary liquid mixture under uncertainty

Speeds of sound in liquid n-heptane, n-octane and their binary mixtures were measured at the tem-peratures T = 293.15 to 523.15 K and pressures up to 60 MPa. The pulse-echo method with a fre-quency of 8 MHz and uncertainty of ±0.08% was used. Measured values was fitted to a poly-nomial equation as functions of temperature and pressure described by interval numbers, and the reliability of the present results were compared with the literature data.