What is the standard unit of pressure measurement used in aviation?

The standard unit of pressure measurement used in aviation is inches of mercury (Hg). This unit is commonly used in altimetry for measuring atmospheric pressure, which is critical for determining altitude in aircraft. The altimeter in an airplane is calibrated to indicate altitude based on the barometric pressure, which is often measured in inches of mercury.

In aviation, a standard atmosphere is defined, and pressure is measured against this reference. It is essential for pilots to understand how to interpret pressure measurements in inches of mercury when flying, as this directly relates to altitude performance and navigation.

While other units like Pascals, pounds per square inch, and atmospheres are used in various engineering and scientific contexts, inches of mercury remains the primary standard for aviation pressure measurement. This ensures uniformity and consistency in pressure readings across different aircraft and altimeter settings, which is vital for safety and operational effectiveness.