Describe measurements of pressure?

Pressure is typically measured in units of force per unit area, such as pounds per square inch (psi) or pascals (Pa). It can also be measured in atmospheres (atm), millimeters of mercury (mmHg), or bars. Pressure can be measured using instruments such as manometers, barometers, or pressure gauges. The measurement of pressure is important in various fields such as meteorology, engineering, and medicine.

Absolute Pressure

- Measured relative to a perfect vacuum, which is assigned a value of zero.
- Units: pascals (Pa), pounds per square inch (psi), atmospheres (atm)

Gauge Pressure

- Measured relative to ambient pressure, which is typically taken as atmospheric pressure.
- Units: psi, inches of mercury (inHg), pounds per square foot (psf)

Vacuum Pressure

- Measured relative to atmospheric pressure, indicating a pressure below ambient.
- Units: inHg, feet of water (ftH2O)

Differential Pressure

- Measures the difference in pressure between two points.
- Units: Pa, psi, inHg

Common Conversion Factors

- 1 atm = 101,325 Pa = 14.7 psi
- 1 psi = 6,895 Pa = 0.068 atm
- 1 inHg = 3,386 Pa = 0.491 psi