Variation of measured sound speeds in gaseous and liquid air with temperature and pressure

Based on sound speeds in gaseous and liquid air measured by Younglove and F rederick [Int. J. Thermophys. 13(6), 1033-1041 (1992)], empirical equations for the computation of sound speeds in the above media at relatively small er temperature and pressure ranges were derived. For gaseous air, over a te mperature range from 200 to 300 K and pressure from 0.614 to 10.292 MPa, th e maximum deviation between the measured sound speeds and those computed wi th the empirical equation is 56 ppm. For liquid air, over the ranges from 9 0 to 110 K for temperature and from 0.763 to 13.823 MPa for pressure, the c orresponding deviation is 173 ppm. [S0001-4966(00)01508-3].