<P> A millimeter of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high and now defined as precisely 7002133322387415000 ♠ 133.322 387 415 pascals . It is denoted by the symbol mmHg or mm Hg . </P> <P> Although not an SI unit, the millimeter of mercury is still routinely used in medicine, meteorology, aviation, and many other scientific fields . </P>

The value of pressure represented by 1 mm of hg