Pascal (unit) dB SPL, or 20 µPa. The airtightness of buildings is measured at 50 Pa. The units of atmospheric pressure commonly used in meteorology were formerly the bar, which was close to the average air pressure on Earth, and the millibar. Since the introduction of SI units, meteorologists generally measure pressures in hectopascals (hPa) unit, equal to 100 pascals or 1 millibar. Exceptions include Canada, which use kilopascals (kPa). In many other fields of science, the SI is preferred, which means Pa with a prefix (in multiples of 1000) is preferred. Many countries also use the millibars. In practically all other
Bar (unit) safety for offshore petrochemical facilities would be expected to exclusively refer to explosion loads in units of bar or bars. A bar is a convenient unit of measure for pressures generated by low frequency vapor cloud explosions that are commonly considered as part of accidental loading risk studies. In the automotive field, turbocharger boost is often described in bars outside the USA. Tire pressure is often specified in bar. Unicode has characters for "mb" (㏔, U+33D4) and "bar" (㍴, U+3374), but they exist only for compatibility with legacy Asian encodings and are not intended to be used in new documents.