Millimetre of mercury
Manometric unit of pressure
A millimetre of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high. Currently, it is defined as exactly 133.322387415 pascals, or approximately 1 torr = 1/760 atmosphere = 101325/760 pascals. It is denoted mmHg or mm Hg.
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