![]() ![]() ![]() The better agreement of our results with those of Wilson may be fortuitous since our measurements were made relative to his pure‐water data. These tables have been prepared from an empirical formula which was derived to fit measured soundspeed data obtained over the temperature range 3C to 30C, the pressure range 1.033 kg/cm 2 to 1000 kg/cm 2, and the salinity range 33 to 37. Over the oceanic range our results agree on the average with the work of Wilson to 0.3 msec −1 (maximum deviation 0.6 msec −1), and with the work of Del Grosso to 0.5 msec −1 (maximum deviation 0.9 msec −1). Tables for the speed of sound in sea water are presented. Although the Chen and Millero/UNESCO equation is the internationally accepted standard (Fofonoff and Millard, 1983) for calculating sound-speed in seawater, scientists have questioned whether it is the best option for all applications (e.g. Our results agree with the work of Wilson on the average to 0.36 msec −1 over the range of 5 to 40 o/oo salinity, 0° to 30☌, and 0 to 1000 bars. where the speed of sound in seawater (C) is in meters per second, temperature (T) is in degrees Celsius, salinity (S) is in parts per thousand (), and depth (Z). Sound Frequency and Air Humidity - The speed and attenuation of sound in moist air varies with sound frequency and air humidity. This equation has been combined with the refitted high‐pressure pure‐water sound‐speed equation of Wilson, Chen and Millero, and the 1‐atm seawater sound‐speed data of Millero and Kubinski to calculate the speeds of sound for seawater at various salinities, temperatures, and pressures. Seawater - Properties - Seawater properties like density, saturation pressure, specific heat, electrical conductivity and absolute viscosity. The result is in m/s, and then, if needed, you have to convert it to other speed units. You can derive these results by applying the formula cair 331.3 × (1 + T/273.15), where T 20C. The effect of pressure on the relative speeds of sound, ( U P− U P H 2O) ‐ U O− U O H 2O), have been fitted to an equation of the form (with a standard deviation of 0.19 msec −1) ( U P− U P H 2O) ‐ ( U O− U O H 2O) = A S (°/oo)+ B S (°/oo) 3/2 + C S (°/oo) 2, where U and U H 2 0 are the speeds of sound in seawater and pure water, respectively superscripts P and O are used to denote applied pressure P and O (1 atm) A, B, and C are temperature‐ and pressure‐dependent parameters S ( o/oo) is the salinity in parts per thousand. Assuming the air temperature of 20 C, the speed of sound is: 343.14 m/s 1235.3 km/h 1125.8 ft/s or 767.6 mph. The speed of sound in standard seawater (diluted with pure water and evaporated) have been measured relative to pure water with a Nusonics single‐transducer sound velocimeter as a function of salinity (5–40°/00), temperature 0°–40☌, and applied pressure (0–1000 bars). ![]()
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