Barometric pressure is just the same as
atmospheric pressure. It is called barometric pressure because the instrument
used to measure is called barometer. It is the pressure exerted by the air at a
certain altitude. Since it is the pressure exerted by the air, it is also known
as the weight of the air above the Earth. Depending on the altitude at which
the measurement is done, barometric or atmospheric pressure varies, but the
barometric pressure at sea level is 1 atm (atmosphere). It is equivalent to
101325 Pa (Pascal), 760 torr, 760 mm Hg and 1.01325 bar.
