Inches of Mercury (inHg) – An Imperial Unit for Pressure

Theinches of mercury (inHg)is an imperial unit of pressure often used in aviation and meteorology. It measures the height of a mercury column in inches and is particularly useful for describing atmospheric pressure.

History & Background

Developed during the era of mercury barometers, inHg has been used for over a century to quantify atmospheric pressure. It remains popular in countries that use the imperial system, especially in weather reporting and aircraft instrumentation.

Conversion Factors

• 1 inHg ≈ 3386.39 Pa
• 1 inHg ≈ 3.38639 kPa
• 1 inHg ≈ 0.0338639 bar
• 1 inHg ≈ 0.491154 atm

Applications

Inches of mercury are used to report barometric pressure in weather forecasts and to monitor cabin pressure in aircraft, ensuring safe and efficient flight operations.

Interesting Facts

Many pilots and meteorologists are accustomed to reading inHg values when assessing weather conditions and atmospheric pressure.

Conclusion

Inches of mercury provide an accessible, imperial-based measure of pressure that is especially valuable in aviation and weather forecasting.