Bars to Millimeters Of Mercury (bar to mmHg)
1 bar equals 750.0615758 millimeters of mercury (rounded).
How to convert bars to millimeters of mercury
To convert bars to millimeters of mercury, multiply the number of bars by 750.0615758. The factor is rounded to 10 significant digits. To go the other way, multiply millimeters of mercury by 0.001333223874 (rounded).
millimeters of mercury = bars × 750.0615758
Example: 10 bars = 7,500.615758 millimeters of mercury.
About these units
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
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
Related conversions
- Millimeters of mercury to bars (reverse)
- Bars to pascals
- Bars to kilopascals
- Bars to standard atmospheres
- Bars to PSI
- Bars to hectopascals
- Bars to megapascals
- Bars to millibars
- Bars to torr
- Bars to inches of mercury
- Bars to gigapascals
- Bars to kilopounds per square inch
- Bars to millimeters of water
- Pascals to millimeters of mercury
- Kilopascals to millimeters of mercury
- Standard atmospheres to millimeters of mercury
- PSI to millimeters of mercury
- Hectopascals to millimeters of mercury
- Megapascals to millimeters of mercury
- Millibars to millimeters of mercury
- Torr to millimeters of mercury
- Inches of mercury to millimeters of mercury
See all pressure units.