The bar (from Greek βαρύς Barys, hard ') is in physics and engineering is a legal entity (outside the International System of Units SI) for printing.
On 1 January 1978, the Bar, the units dissolved in the Federal Republic of Germany and in Austria from physical atmosphere ( atm short ) and technical atmosphere ( at short ). The widespread abbreviation atm (atmospheric pressure ) is replaced by " bar overpressure ." The International System of Units uses the Pascal as a measure of the pressure. On January 1, 1980, Pascal was introduced as a compulsory measure of the pressure in the GDR and the old units kgf / cm ², and at mwc (atmosphere) or atm were no longer permitted. According to the EU Directive Directive 80/181/EEC the unit bar can still be used.
1 bar is approximately to the atmospheric pressure on the surface. At the same time, the pressure increases, the hydrostatic pressure per 10 meters water depth.
- 1 mbar = 1 hPa = 100 Pa
In order to
Bar relative and absolute
In everyday use, the pressure is often measured and reported relative to atmospheric pressure: If the tire pressure monitor a pressure of 2.3 bar (g) displays at the gas station, then the pressure in car tires actually 2.3 bar ( g) above atmospheric pressure ( approximately 1 bar ), ie about 3.3 bar (a) absolute.
- Diving physics
- Pressure unit
- Legal entity in the EU
- Legal unit in Switzerland