Millimeters Of Mercury to Bars (mmHg to bar)
1 millimeter of mercury equals 0.001333223874 bars (rounded).
How to convert millimeters of mercury to bars
To convert millimeters of mercury to bars, multiply the number of millimeters of mercury by 0.001333223874. The factor is rounded to 10 significant digits. To go the other way, multiply bars by 750.0615758 (rounded).
bars = millimeters of mercury × 0.001333223874
Example: 10 millimeters of mercury = 0.01333223874 bars.
About these units
Millimeter Of Mercury (mmHg)
About 133.322 pascals, the pressure from a 1 mm column of mercury. Blood pressure is still reported in mmHg.
Where the torr honors a person, the millimeter of mercury describes a gauge. It is a manometric unit: originally the pressure from a mercury column 1 mm tall, which means it depends on an assumed fluid density and on gravity. Mercury manometers were among the first accurate pressure gauges, and 17th-century experiments by Torricelli and then Pascal, whose mercury stood at about 23 inches on a mountaintop against about 26 at its base, showed that air has weight and that pressure drops with altitude.
To remove the ambiguity, mmHg is now fixed at exactly 133.322387415 Pa, using a conventional mercury density of 13,595.1 kg per cubic meter and standard gravity. The torr, defined as one 760th of a standard atmosphere, differs from it by only about 0.000015 percent.
Mercury is toxic and its readings vary with temperature and local gravity, so mercury gauges are now used less, and the unit's use is discouraged. Medicine nonetheless keeps it, especially for blood pressure, which is reported relative to atmospheric pressure, and hypertension guidelines in the US and Europe still use it.
1 millimeter of mercury = 133.3223874 pascals (approximately).
Sources: Wikipedia: Millimetre of mercury; Wikipedia: Torr; Wikipedia: Blaise Pascal
Bar (bar)
Exactly 100,000 pascals, close to atmospheric pressure at sea level. Used for tire pressure, diving and industrial gauges.
Bar began as a name that meant different things to different people. It comes from the Ancient Greek baros, weight, and from 1793 to 1795 an early metric system used bar for a unit of mass equal to the modern tonne. The pressure bar was introduced by the Norwegian meteorologist Vilhelm Bjerknes, a founder of modern weather forecasting, who defined it as one megadyne per square centimeter. Some earlier writers had used bar for one dyne per square centimeter, a source of confusion.
The bar is a metric unit but not part of the SI, and its official symbol is simply bar, since the old b clashes with the barn and the bit. It has been legally recognized in EU countries since 2004, although NIST deprecates it except for limited use in meteorology.
Its size is handy because 1 bar is slightly less than average sea-level pressure, which is about 1.013 bar. In scuba diving every 10 meters of seawater adds about 1 bar and a full standard tank holds about 200 bar. Tire pressure and turbocharger boost are often quoted in bar outside the US.
1 bar = 100,000 pascals (exactly).
Sources: Wikipedia: Bar (unit); Wikipedia: Atmospheric pressure
Related conversions
- Bars to millimeters of mercury (reverse)
- Millimeters of mercury to pascals
- Millimeters of mercury to kilopascals
- Millimeters of mercury to standard atmospheres
- Millimeters of mercury to PSI
- Millimeters of mercury to hectopascals
- Millimeters of mercury to megapascals
- Millimeters of mercury to millibars
- Millimeters of mercury to torr
- Millimeters of mercury to inches of mercury
- Pascals to bars
- Kilopascals to bars
- Standard atmospheres to bars
- PSI to bars
- Hectopascals to bars
- Megapascals to bars
- Millibars to bars
- Torr to bars
- Inches of mercury to bars
- Gigapascals to bars
- Kilopounds per square inch to bars
- Millimeters of water to bars
See all pressure units.