Atmospheric Pressure ↓↓↓4↓ Mercury Atmospheric pressure is usually measured using a mercury barometer Patm =phg g ha 101, 300 N/m2 abs 0N/m2 gauge ≈1.013 bar abs ≈760 mm hg abs ≈10.3 m water absAtmospheric Pressure Atmospheric pressure is usually measured using a mercury barometer Patm = ρHg g h  101,300 N/m2 abs = 0 N/m2 gauge  1.013 bar abs  760 mm Hg abs  10.3 m water abs