Air pressure can be expressed using different units of measure, such as atmospheres (atm), kilopascals (kPa), kilogram per square meter (kg/m2), millibars (mb), millimeters of Mercury (mmHg), and pounds-force per square inch (psi). The conversion to atm units depends on what units your original value are in.
To see how the different units compare, 1 atm is equal to:
760 torr
101.3 kPa (kilopascals)
0.1013 MPa (megapascals)
101325 Pa (pascals)
760 mmHg (millimeters of mercury)
29.92 inHg (inches of mercury)
1.013 bars
1013 mbar (millibars)
14.7 psi (pounds-force per square inch)
2116 lbf/ft^2 (pounds-force per square foot)
The standard measure of pressure (i.e the SI unit) is the pascal, but the kilopascal (kPa) is usually used for measuring atmospheric pressure. As such, here is the formula used to convert atm to kpa:
Pressure in atm = kPa value / (101.325 kPa/atm)
For example, to convert the pressure of 99.5 kPa into atm: = 99.5 kPa / (101.325 kPa)
= 0.98198865 atm
If you mean inches of mercury
1 atmosphere = 29.92 inches of mercury = 760 mm of mercury = 760 Torr = 101325 Pa = 1013.25 mb = 1013.25 hPa = 101.325 kPa.
So you just multiply by the one you want and divide by the one you have.
99.1 kPa * (29.92 inches Hg/101.325 kPa) = 29.26 inches.
if the units you're looking for are atmospheres (ATMs), divide your pressure by atmospheric pressure. In this case, that would be 406.8 inches of H20.
One inch of mercury is equal to 25.397 mm of mercury. There is no special conversion needed because what is being measured is the height of the mercury in the column.
PSIA = .491130 x inHg
To convert kPa (which means absolutely nothing to me) to Pounds per Square Inch (P.S.I.) multiply by 0.1450377, or divide by 6.894757293. To convert P.S.I. to Inches of mercury, multiply by 2.0359281, to convert Inches of mercury to P.S.I., multiply by 0.4911765
PSIG refers to pound/force per square inch gauge, while PSI measures the pressure relative to a vacuum. If you want to convert a figure from PSIG to PSI, you would need to add 14.7psi to your PSIG figure, which will give you your PSIA result.
PSIA is Pounds per Square Inch Absolute, as opposed to PSIG which is PSI Gauge. PSIA is absolute pressure. For example, normal atmospheric pressure is about 14.7 PSIA, so a PSIA device connected to atmosphere would read 14.7. PSIG is relative pressure, so if system pressure is 15.7 PSIA, and atmospheric pressure is 14.7 PSIA, then PSIG would be 1.0
-24.43 inches of mercury.
24.34 inches of mercury = 618.2 Torr
Multiply by 2.03625437 to convert from psi to inches mercury. Multiply by 0.49109777 to convert from inches mercury to psi.
kPa x 0.2953 = inches of mercury
Inches of mercury x 3,386.389 = Pascals
Multiply inches of mercury by 0.033421057 to get atmospheres.
Inches of mercury x 0.4912 = psi
psia to psig psig - 15 15 - 15= 0 psig
One inch of mercury is equal to 33.9 millibars. So: inches of mercury x 33.9 = millibars.
add atmosperic pressure to gage pressure to convert to psia one atm standard = 14.7 psi
To convert kPa (which means absolutely nothing to me) to Pounds per Square Inch (P.S.I.) multiply by 0.1450377, or divide by 6.894757293. To convert P.S.I. to Inches of mercury, multiply by 2.0359281, to convert Inches of mercury to P.S.I., multiply by 0.4911765
Inches of mercury x 0.4912 equals psi
Use the web site: http://www.convert-me.com/en/convert/pressure#in*mercury Which also shows the relevant conversion factors.
PSIG refers to pound/force per square inch gauge, while PSI measures the pressure relative to a vacuum. If you want to convert a figure from PSIG to PSI, you would need to add 14.7psi to your PSIG figure, which will give you your PSIA result.