Calculation of the Air Density

The Bar and the Pascal are units of pressure, which has the dimensions of force/area. This may help: http://www.simetric.co.uk/.

The properties of dry air may be found in published volumes of steam tables, like Mayhew & Rogers.

For the density of air, you can calculate density at various temps and pressures by using the ideal gas law (PV = nRT). There is lots of info on the net about this so I will not go into further detail.

As for the units, Pascal and bar are pressure units defined as:

Pascal [Pa] = 1N/m²

Bar = 100,000Pa

If you are interested in how why these units are named, try a web search, maybe Wikipedia.

fm!

1 bar = 1 atmosphere.

not really correct:

1atmosphere=1.01325bar

see http://en.wikipedia.org/wiki/Atmosphere_%28unit%29

Density of dry air at 0°C and 1 bar absolute is 1.27 kg/m³ near enough for most purposes. At other temp T°C and pressure P bar density = 1.27*P*273/(273 + T) kg/m³. Note pressures are absolute.

Cheers....Codey

Yep, and so are the temperatures . . .

Hello Bill - not in my formula. There's 273 in the denominator so T is in °C. I suppose to be consistent with P being absolute, should say 1.27*P*273/T kg/m³, T in °K, but it works either way.

Codey