Inches of Mercury
- Inches of mercury is commonly used in the United States in weather forecasting and the aviation and refrigeration industries
1 inch of mercury is the pressure exerted by a 1 inch high column of mercury at 0 °C (32 °F )
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.
- 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
Used in weather forecasting and the aviation and refrigeration industries