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InHg
Inch of mercury (inHg and ″Hg) is a non- SI unit of measurement for pressure. It is used for barometric pressure in weather reports, refrigeration and aviation in the United States. It is the pressure exerted by a column of mercury in height at the standard acceleration of gravity. Conversion to metric units depends on the temperature of mercury, and hence its density; typical conversion factors are: In older literature, an "inch of mercury" is based on the height of a column of mercury at .Barry N. Taylor, ''Guide for the Use of the International System of Units (SI),'' 1995, NIST Special Publication 811, Appendix /ref> :1 inHg60 °F = In Imperial units: 1 inHg60 °F = 0.489 771 Pounds per square inch, psi, or 2.041 771 inHg60 °F = 1 psi. Applications Aircraft and automobiles Aircraft altimeters measure the relative pressure difference between the lower ambient pressure at altitude and a calibrated reading on the ground. In t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barometric Pressure
Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 760 mm Hg, 29.9212 inchesHg, or 14.696 psi.International Civil Aviation Organization. ''Manual of the ICAO Standard Atmosphere'', Doc 7488-CD, Third Edition, 1993. . The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth; that is, the Earth's atmospheric pressure at sea level is approximately 1 atm. In most circumstances, atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. As elevation increases, there is less overlying atmospheric mass, so atmospheric pressure decreases with increasing elevation. Because the atmosphere is thin relative to the Earth's radius—especially the dense atmospheric layer at low altitudes—the E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Brake
The vacuum brake is a braking system employed on trains and introduced in the mid-1860s. A variant, the automatic vacuum brake system, became almost universal in British train equipment and in countries influenced by British practice. Vacuum brakes also enjoyed a brief period of adoption in the United States, primarily on narrow-gauge railroads. Their limitations caused them to be progressively superseded by compressed air systems starting in the United Kingdom from the 1970s onward. The vacuum brake system is now obsolete; it is not in large-scale usage anywhere in the world, other than in South Africa, largely supplanted by air brakes. Introduction In the earliest days of railways, trains were slowed or stopped by the application of manually applied brakes on the locomotive and in brake vehicles through the train, and later by steam power brakes on locomotives. This was clearly unsatisfactory, given the slow and unreliable response times (each brake being separately applied ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altimeter
An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth under water. The most common unit for altimeter calibration worldwide is hectopascals (hPa), except for North America (other than Canada ) and Japan where inches of mercury (inHg) are used. To obtain an accurate altitude reading in either feet or meters, the local barometric pressure must be calibrated correctly using the barometric formula. History The scientific principles behind the altimeter were first written by Rev. Alexander Bryce a Scottish minister and astronomer in 1772 who realised that the principles of a barometer could be adjusted to measure height. Pressure altimeter Altitude can be determined based on the measurement of atmospheric pressure. The greater the altitude, the lower the pressure. When a barometer is supplied with a nonlinear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bar (unit)
The bar is a metric unit of pressure, but not part of the International System of Units (SI). It is defined as exactly equal to 100,000 Pa (100 kPa), or slightly less than the current average atmospheric pressure on Earth at sea level (approximately 1.013 bar). By the barometric formula, 1 bar is roughly the atmospheric pressure on Earth at an altitude of 111 metres at 15 °C. The bar and the millibar were introduced by the Norwegian meteorologist Vilhelm Bjerknes, who was a founder of the modern practice of weather forecasting. The International System of Units, despite previously mentioning the bar, now omits any mention of it.. The bar has been legally recognised in countries of the European Union since 2004. British Standard BS 350:2004 ''Conversion Factors for Units''. The US National Institute of Standards and Technology (NIST) deprecates its use except for "limited use in meteorology" and lists it as one of several units that "must not be i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight Level
In aviation and aviation meteorology, a flight level (FL) is an aircraft's altitude at standard air pressure, expressed in hundreds of feet. The air pressure is computed assuming an International Standard Atmosphere pressure of 1013.25 hPa (29.92 inHg) at sea level, and therefore is not necessarily the same as the aircraft's actual altitude, either above sea level or above ground level. Background Flight levels are used to ensure safe vertical separation between aircraft, despite natural local variations in atmospheric air pressure. Historically, altitude has been measured using a pressure altimeter, which is essentially a calibrated barometer. An altimeter measures ambient air pressure, which decreases with increasing altitude following the barometric formula. It then calculates and displays the corresponding altitude. If different aircraft's altimeters were not calibrated consistently, then two aircraft could be flying at the same altitude even though their alti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mbar
The bar is a metric unit of pressure, but not part of the International System of Units (SI). It is defined as exactly equal to 100,000 Pa (100 kPa), or slightly less than the current average atmospheric pressure on Earth at sea level (approximately 1.013 bar). By the barometric formula, 1 bar is roughly the atmospheric pressure on Earth at an altitude of 111 metres at 15 °C. The bar and the millibar were introduced by the Norwegian meteorologist Vilhelm Bjerknes, who was a founder of the modern practice of weather forecasting. The International System of Units, despite previously mentioning the bar, now omits any mention of it.. The bar has been legally recognised in countries of the European Union since 2004. British Standard BS 350:2004 ''Conversion Factors for Units''. The US National Institute of Standards and Technology (NIST) deprecates its use except for "limited use in meteorology" and lists it as one of several units that "must not be introd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Champ Car
Champ Car World Series (CCWS) was the series sanctioned by Open-Wheel Racing Series Inc., or Champ Car, a sanctioning body for American open-wheel car racing that operated from 2004 to 2008. It was the successor to Championship Auto Racing Teams (CART), which sanctioned the 'PPG Indy Car World Series from 1979 until dissolving after the 2003 season. Vehicles Champ Cars were single-seat, open-wheel racing cars, with mid-mounted engines. Champ cars had sculpted undersides to create ground effect and prominent wings to create downforce. The cars would use a different aerodynamic kit on the occasions they raced on an oval. With funds low, development was effectively frozen with a focus on developing a universal chassis, and the series generally ran on CART-spec 2002 Lola chassis from 2003 to 2006. The new chassis was developed by Panoz and debuted in 2007 as the Panoz DP01. The chassis was well received by drivers and fans. The series leased 750hp 2.65 L V-8 turbocharg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Auto Club
The United States Auto Club (USAC) is one of the sanctioning bodies of auto racing in the United States. From 1956 to 1979, USAC sanctioned the United States National Championship, and from 1956 to 1997 the organization sanctioned the Indianapolis 500. Today, USAC serves as the sanctioning body for a number of racing series, including the Silver Crown Series, National Sprint Cars, National Midgets, Speed2 Midget Series, .25 Midget Series, Stadium Super Trucks, and Pirelli World Challenge. Seven-time USAC champion Levi Jones is USAC's Competition Director. History When the American Automobile Association (AAA) withdrew from auto racing after the 1955 season, citing the Le Mans disaster and the death of Bill Vukovich at Indianapolis as contributing factors, both the SCCA and NASCAR were mentioned as its potential successor. Ultimately, USAC was formed by Indianapolis Motor Speedway owner Tony Hulman. It became the arbiter of rules, car design, and other matters for what ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indy Car Racing
Indy may refer to: Computing and technology * Indy (software), used for Internet access to music *Internet Direct, or "Indy", a software library * SGI Indy, a computer workstation Periodicals *''The Indy'', shorthand for newspapers that include "Independent" in their name, e.g.: **'' The Independent (Newfoundland)'', published in Newfoundland and Labrador, Canada **''The Independent'', a daily British newspaper **'' The College Hill Independent'', published in Providence, Rhode Island **''The Indydependent'', a newspaper published by the Independent Media Center (also known as "Indymedia" or "Indy Media") Sports *Indianapolis 500, also known as "Indy 500", a car race *Indy Eleven, Indianapolis' United Soccer League team * Indy Fuel, Indianapolis' ECHL ice hockey team *Indy grab, a board-sport maneuver Other uses *Indy (gene), a fruit-fly longevity gene * ''Indy'' (album), the second EP by Motograter * Independence High School (San Jose, California), also referred to as Indy, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercharger
In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced induction that is mechanically powered (usually by a belt from the engine's crankshaft), as opposed to a turbocharger, which is powered by the kinetic energy of the exhaust gasses. However, up until the mid-20th century, a turbocharger was called a "turbosupercharger" and was considered a type of supercharger. The first supercharged engine was built in 1878, with usage in aircraft engines beginning in the 1910s and usage in car engines beginning in the 1920s. In piston engines used by aircraft, supercharging was often used to compensate for the lower air density at high altitudes. Supercharging is less commonly used in the 21st century, as manufacturers have shifted to turbochargers to reduce fuel consumption and/or increase power outputs. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manifold Pressure
Manifold vacuum, or engine vacuum in an internal combustion engine is the difference in air pressure between the engine's intake manifold and Earth's atmosphere. Manifold vacuum is an effect of a piston's movement on the induction stroke and the choked flow through a throttle in the intake manifold of an engine. It is a measure of the amount of restriction of airflow through the engine, and hence of the unused power capacity in the engine. In some engines, the manifold vacuum is also used as an auxiliary power source to drive engine accessories and for the crankcase ventilation system. Manifold vacuums should not be confused with Venturi vacuums, which are an effect exploited in carburetors to establish a pressure difference roughly proportional to mass airflow and to maintain a somewhat constant air/fuel ratio. It is also used in light airplanes to provide airflow for pneumatic gyroscopic instruments. Overview The rate of airflow through an internal combustion engine is an im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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