The speed of sound of <Emphasis Type="Italic">n</Emphasis>-heptane, <Emphasis Type="Italic">n</Emphasis>-octane and their binary mixtures at temperatures <Emphasis Type="Italic">T</Emphasis> = 293.15 to 523.15 K and pressures up to 60 MPa

Speeds of sound in liquid n-heptane, n-octane and their binary mixtures were measured at the temperatures T = 293.15 to 523.15 K and pressures up to 60 MPa. The pulse-echo method with a frequency of 8MHz and uncertainty of ±0.08% was used. The measured values were fitted by polinomials, as functions of temperature and pressure, and the reliability of the present results was proved by comparison with the literature data.