Pressure millimeter of mercury

Millimeters of mercury, pressure unit mmHg Ultraviolet uv... 

WATER. A colorless (blue in thick layers) liquid, H2O or HOH. odorless, tasteless, melting point 0°C (one of the standard temperature points), boiling point 100°C at 760 millimeters of mercury pressure (turnliter standard temperature point). 

TABLE 5.4 Vapor Pressure of Ice in Millimeters of Mercury For temperatures from —99 to 0°C. 

The percent relative humidity is defined as lOOp/P, where p is the actual partial pressure of the water vapor and P is the vapor pressure of water at the same temperature. The total pressure is taken as normal barometric, unless otherwise stated. Note that since the per cent relative humidity is defined as 100(p/Pj) and the per cent absolute humidity equals 100[p/(760-p) -h P,/(760-Pj)], the factor by which the former must be multiplied to convert it to the latter is (760 -P ) / (760-p), where p and Pj can be expressed in units of millimeters of mercury. 

A number of units are used to express a pressure measurement. Some are based on a force per unit area for e.xample, pound (force) per square inch (psi) or dyne per square centimeter (dyne/enr). Otliers are based on a fluid height, such as inches of water (in H O) or millimeters of mercury (iimiHg) units such as these are convenient when tlie pressure is indicated by a difference between two levels of a liquid, as in a imuiometer or barometer. Barometric pressure is a measure of the ambient air pressure. Standard barometric pressure is 1 atm and is equivalent to 14.696 psi and 29.921 in Hg. 

Fcr piping with air in streamline flow at absolute pressures in the range between 50 microns and 1 millimeter of mercury, the following is a recommended method. Calculation procedures in pressure regions below atmospheric are very limited and often not generally applicable to broad interpretations. 

D-1160 is run under vacuum (one millimeter of mercury). The results are converted to atmospheric pressure, using standard cor relations. Some newer apparatuses have built-in software that performs the conversion automatically. D-1160 is limited to a maximum EP temperature of about 1,000°F (538°C) at atmospheric pressure. Above this temperature, the sample begins to crack thermally. 

Because of the way in which gas pressure is measured, it is often expressed in millimeters of mercury (mm Hg). Thus we might say that the atmospheric pressure on a certain day is 772 mm Hg. This means that the pressure of the air is equal to that exerted by a column of mercury 772 mm (30.4 in) high. 

The pressure exerted by a column of mercury depends on its density, which varies slightly with temperature. To get around this ambiguity, the torr was defined to be the pressure exerted by 1 mm of mercury at certain specified conditions, notably 0°C. Over time, the unit torr has become a synonym for millimeter of mercury. Throughout this text, we will use millimeter of mercury rather than torr because the former has a clearer physical meaning. 

The height of the mercury in the system-side column of an open-tube mercury manometer was 10. mm above that of the open side when the atmospheric pressure corresponded to 756 mm of mercury and the temperature was 15°C. What is the pressure inside the apparatus in millimeters of mercury and in pascals ... 

Self-Test 4.2B What is the pressure in millimeters of mercury inside a system when a closed mercury manometer shows a height difference of 10. cm at 15°C ... 

The standard pressure for reporting data is now defined as 1 bar exactly- However, it had long been conventional to report data in terms of a pressure corresponding to 760 millimeters of mercury (written 760 mmHg), corresponding to just over 101 kPa. This convention inspired the use of the unit the atmosphere (atm), which is now defined by the exact relation... 

The unit millimeter of mercury (mmHg) is defined in terms of the pressure exerted by a column of mercury under certain conditions (15°C and in a standard gravitational field), bur it has now been largely displaced by a unit of similar magnitude, the torr (Torr). This unit is defined by the exact relation... 

One of the commonest forms of gas discharges is a glow discharge which is formed at gas pressures of a few tenths to several millimeters of mercury and is characterized by the presence of a well defined dark... 

Boiling Point. Such points/ranges are distinguished from melting points and ranges by the presence of a pressure in millimeters of mercury (mmHg) after the temperature for example, 97-98/0.5. 

We must combine the reading from the manometer with the barometric pressure to find the pressure of the gas sample. The manometer displays the pressure difference in millimeters of mercury, so conversion factors are needed to express the pressure in atmospheres and bars. 

VP Vapor pressure of the material in millimeters of mercury (mmHg) at 68°F. If another temperature is used, it is indicated in parentheses following the vapor pressure. 

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