Millibar (mbar, mb or mbr)

Millibar is a metric unit of pressure mainly used in European countries and is derived directly from the bar pressure unit which equals 1,000 mbar. In SI units 1 mbar equals 100 pascals.
The millibar is most commonly used to measure barometric pressure for meteorological purposes and low range gas pressures due to its very small value.

In recent years the mb pressure unit has been replaced by the hPa (hectopascal) which is exactly the same value. However the mbar has been used by many people for many years so it will be a long time before its use is completely phased out if at all.
There are three common abbreviated forms used to identify millibar pressure unit which are mb, mbar and mbr.