Inch of mercury (inHg and "Hg) is a unit of measurement for pressure. It is still used for barometric pressure in weather reports, refrigeration and aviation in the United States.
millipascals
The millipascal is a multiple of the unit bit for Pressure. The prefix milli (symbol m) is defined in the International System of Units (SI) as a multiplier of 1 × 10-3 (1 thousandth, short scale), and therefore 1 millipascal = 1 × 10-3 pascals = 0.001 pascals. The millipascal has the unit symbol mPa.