Calculation of B/A for Water from Measurements of Ultrasonic Velocity versus Temperature and Pressure to 10 000 kg/cm2

New measurements of the velocity of sound in water over a wide range of temperatures and pressures have been made and are used to calculate the nonlinearity parameter B/A in the temperature range from 0° to 80°C and at pressures to about 10 000 kg/cm2. It is found that, for low temperatures, B/A rises to a broad maximum at about 3000 kg/cm2 and then slowly decreases. At the highest temperatures, B/A decreases very slowly with increasing pressure. At 1 atm pressure, the B/A value for 0°C is the lowest calculated at any temperature and pressure, and B/A increases monotonically with temperature in the range covered. However, at 3000 kg/cm2, the B/A value for 0°C is the largest obtained, and B/A decreases with increasing temperature. The values of B/A range from a low value of 4.08 at 1 atm and 0°C to 6.80 at 3000 kg/cm2 and 0°C. B/A is found to be relatively insensitive to temperature and pressure. The usefulness of B/A measurements as a means of studying the liquid state is discussed.