Units of Pressure
Pressure (or stress) has the dimension mass per length time squared. The SI unit of pressure is the pascal, which is defined as a newton per square meter, or a kilogram per meter second squared.
Maple knows the units of pressure listed in the following table.
atm @, atmos@
meters_mercury, metre_mercury, metres_mercury
meters_water, metre_water, metres_water
An asterisk ( * ) indicates the default context, an at sign (@) indicates an abbreviation, and under the prefixes column, SI indicates that the unit takes all SI prefixes, IEC indicates that the unit takes IEC prefixes, and SI+ and SI- indicate that the unit takes only positive and negative SI prefixes, respectively. Refer to a unit in the Units package by indexing the name or symbol with the context, for example, pascal[SI] or mmHg[standard]; by using an abbreviation, for example, at; or, if the context is indicated as the default, by using only the unit name or symbol, for example, pascal or mmHg.
The units of pressure are defined as follows.
A bar is defined as 100000 pascals.
A standard atmosphere is defined as 101325 pascals.
A technical atmosphere is defined as a kilogramforce per square centimeter, that is, 98066.5 pascals.
A barye is defined as a dyne per square centimeter.
A pieze is defined as a sthene per square meter.
A torr is defined as 1760 standard atmosphere.
A vac is defined as a millibar.
A pound per square inch is defined as a poundforce per inch squared.
A planck pressure is defined as a planck mass per planck length per planck time squared.
The meter, foot, and inch of mercury are the pressures exerted by columns of mercury 1 meter, foot, and inch in height, respectively.
A standard meter of mercury is defined as 2519 atmospheres.
A 0 degree Celsius meter of mercury is defined as approximately 133322 pascals.
A standard foot of mercury is defined as 0.3048 standard meter of mercury.
A 32 degree Fahrenheit foot of mercury is defined as approximately 40636.6 pascals.
A 60 degree Fahrenheit foot of mercury is defined as approximately 40522.2 pascals.
A standard inch of mercury is defined as 0.0254 standard meter of mercury.
A 32 degree Fahrenheit inch of mercury is defined as approximately 3386.38 pascals.
A 60 degree Fahrenheit inch of mercury is defined as approximately 3376.85 pascals.
The meter, foot, and inch of water are the pressures exerted by columns of water 1 meter, foot, and inch in height, respectively.
A standard meter of water is defined as the pressure exerted by 1000 kilograms per square meter assuming standard acceleration of free fall.
A 4 degrees Celsius meter of water is defined as approximately 9806.38 pascals.
A standard foot of water is defined as 0.3048 standard meter of water.
A 39.2 degree Fahrenheit foot of water is defined as approximately 2988.98 pascals.
A standard inch of water is defined as 0.0254 standard meter of water.
A 39.2 degree Fahrenheit inch of water is defined as approximately 249.082 pascals.
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