Standard sea-level conditions (SSL), also known as sea-level standard (SLS), defines a set of atmospheric conditions for physical calculations. The term "standard

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardis ...

" is used to indicate that values of properties are to be taken to be the same as those standard at sea level, and is done to define values for use in general calculations.

Atmospheric properties

At SSL some atmospheric properties are: *

Pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country a ...

, ''P'' = 101.325 kPa ⇔ 2116.2 lb_f/ ft² ⇔ 14.696 lb_f/ in² ⇔ 29.92 inHg *

Density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematicall ...

\rho

= 1.225 kg/m³ ⇔ 0.002377

slug Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a ...

/ft³ *

Temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

, ''T'' = 15

°C The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The d ...

⇔ 288.15 K ⇔ 518.67 °R *

Gas constant The molar gas constant (also known as the gas constant, universal gas constant, or ideal gas constant) is denoted by the symbol or . It is the molar equivalent to the Boltzmann constant, expressed in units of energy per temperature increment per ...

of air, ''R''_air = 287.057 J/(kg·K) ⇔ 1716.59 ft·lb/sl·°R) *

Specific Weight The specific weight, also known as the unit weight, is the weight per unit volume of a material. A commonly used value is the specific weight of water on Earth at , which is .National Council of Examiners for Engineering and Surveying (2005). ''Fu ...

\gamma

= 12.014 N/ m³ ⇔ 0.07647 lb_f/ ft³ *

Dynamic viscosity The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the int ...

\mu

= 1.789×10⁻⁵ Pa·s ⇔ 3.737×10⁻⁷ slug/(s·ft) * Acceleration of gravity, ''g₀'' = 9.807 m/s² ⇔ 32.174 ft/s²

References

Atmosphere {{fluiddynamics-stub

Atmospheric properties

See also

References