altimeter setting[al′tim·əd·ər ‚sed·iŋ]
The value of atmospheric pressure to which the scale of an aneroid altimeter is set; after United States practice, the pressure that will indicate airport elevation when the altimeter is 10 feet (3 meters) above the runway (approximately cockpit height).
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The station pressure corrected for the height of the station above sea level. When this pressure (QNH) is set in the altimeter window (also known as a Kollsman window, the altimeter indicates the height above mean sea level. The setting may be in inches, millibars, or hectopascals. See also QNH.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved