Inches of Mercury

{
  "id": "MLC-T-MET-001384",
  "term": "Inches of Mercury",
  "field": "Meteorology and atmospheric science",
  "definition": "(or in Hg) Unit of atmospheric pressure used in the United States. The name comes from the use of mercurial barometers which equate the height of a column of mercury with air pressure. One inch of mercury is equivalent to 33.86 millibars or 25.40 millimeters. See barometric pressure. First divised in 1644 by Evangelista Torricelli (1608-1647), an Italian physicist and mathematician, to explain the fundamental principles of hydromechanics.\n\nTo convert millibars (mb) to inches of mercury (in Hg), divide the millibar reading by 33.86:\n\nin Hg = mb / 33.86",
  "see_also": [
    "Barometric Pressure"
  ],
  "references": [
    "NWS Glossary"
  ],
  "url": "https://mlchart.com/terminology/meteorology/inches-of-mercury/"
}