Inch of mercury
= Inch of mercury
{wiki=Inch_of_mercury}
An inch of mercury (inHg) is a unit of pressure that is commonly used in various applications, particularly in meteorology and aviation. It is defined as the pressure exerted by a column of mercury that is one inch in height at a specific temperature (usually 0°C or 32°F). The concept originated from early barometers, which used mercury to measure atmospheric pressure. The pressure at sea level is approximately 29.