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Example \(\PageIndex{1}\): Pressure Unit Conversions. The atmospheric pressure in a mountainous location is measured to be \(613 \: \text{mm} \: \ce{Hg}\). What is this pressure in \(\text{atm}\) and in \(\text{kPa}\)?
Pressure is defined as the force exerted per unit area; it can be measured using a barometer or manometer. Four quantities must be known for a complete physical description of a sample of a gas: temperature, volume, amount, and pressure.
In the English system, the pressure unit is pound-force per square inch (psi), where 1 psi 1 lbf/in 2. In either unit system, another popular unit of pressure is standard atmosphere (atm), defined as the pressure at standard temperature and pressure at sea level, 1 atm 101,325 Pa 14.696 psi .
2.1 MEASURING ATMOSPHERIC PRESSURE The atmospheric pressure is the weight exerted by the overhead atmosphere on a unit area of surface. It can be measured with a mercury barometer, consisting of a long glass tube full of mercury inverted over a pool of mercury: Figure 2-1 Mercury barometer When the tube is inverted over the pool, mercury flows ...
28 gru 2020 · Pressure is a key concept in physics, whether you're interested in how meteorologists predict the weather, or you want to describe the Carnot cycle in thermodynamics. Pressure is the force on a surface per unit area, and it has a close link to the temperature of the liquid or gas creating it.
Pressure can be measured directly by measurement of the applied force or indirectly, e.g. by the measurement of the gas properties. Examples of indirect measurement techniques that are using gas properties are thermal conductivity or ionization of gas molecules.
Measuring Pressure. A host of devices are used for measuring pressure, ranging from tire gauges to blood pressure monitors. Many other types of pressure gauges are commonly used to test the pressure of fluids, such as mechanical pressure gauges. We will explore some of these in this section.
