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bar (b)




A unit of pressure, used especially in giving the pressure of a planet's or moon's atmosphere. One bar is the pressure created by a column of mercury 75.006 cm high at 0°C. It is approximately the average pressure at sea-level on the Earth. 1 bar = 0.987 atmospheres = 1.02 kg/cm2 = 100 kilopascals = 14.5 lb/sq. in. Atmospheric pressures are often quoted in millibars (mb), or thousandths of a bar. Standard atmospheric pressure (at sea level) is 1.01325 bars, or 1,013.25 millibars.


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