理解压力

压力是垂直施加在物体表面上的力除以该力分布的单位面积。它是物理学、工程学和气象学中的关键概念。

介绍

Pressure measurement is essential for understanding fluid behavior, atmospheric conditions, and mechanical systems. From tire pressure to weather forecasting, pressure affects safety, performance, and natural phenomena.

历史

Evangelista Torricelli invented the barometer in 1643, leading to the understanding of atmospheric pressure. Blaise Pascal's work on fluid pressure led to Pascal's principle. The pascal was adopted as the SI unit of pressure.

关键单位

Pascal (Pa)

The SI unit of pressure, equal to one newton per square meter.

Bar

Equal to 100,000 Pa, commonly used in meteorology and engineering.

Atmosphere (atm)

Equal to 101,325 Pa, based on standard atmospheric pressure at sea level.

Pounds per square inch (psi)

Equal to 6,895 Pa, widely used in the United States for various applications.

Torr

Equal to 133.3 Pa, used in vacuum technology and medical applications.

Millimeter of mercury (mmHg)

Equal to 133.3 Pa, commonly used in medical blood pressure measurements.

应用

  • Weather forecasting and atmospheric monitoring
  • Automotive tire pressure and safety systems
  • Industrial hydraulic and pneumatic systems
  • Medical blood pressure and respiratory monitoring
  • Vacuum technology and scientific instruments
  • Diving and underwater pressure calculations

Pressure Relationships

P = F/A, P = ρgh

Pressure equals force per unit area, or fluid density times gravity times height.