Vacuum Gage 2 : An instrument for measuring pressures below atmospheric, usually expressed in inches of water or millimeters of mercury. See also: Gage
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}