Inches of Mercury
Abbreviation/Symbol:
- inHg
- "Hg
Unit of:
- Pressure
Worldwide use:
- Inches of mercury is commonly used in the United States in weather forecasting and the aviation and refrigeration industries
Definition:
1 inch of mercury is the pressure exerted by a 1 inch high column of mercury at 0 °C (32 °F )
Origin:
The inch of Mercury was the first accurate measure of pressure. The measurment came about from the invention of mercury manometers, which displayed pressure difference between two fluids as a vertical difference in mercury levels in two connected reservoirs. It is defined as the pressure exerted by a circular column of mercury of 1 inch in height at 32 °F (0 °C) 1 inHg = 3386.389 Pa at 0 °C.
Common references:
- The average sea level pressure is 29.92 inches of mercury. The highest barometric pressure ever recorded on Earth was 32.06 inches of Mercury
Usage context:
Used in weather forecasting and the aviation and refrigeration industries