Convert Bar to Psi

Bar

Definition: A bar (symbol: bar) is a metric unit of pressure that is defined as exactly 100,000 pascals (symbol: Pa). It is equal to 0.987 atmospheres (101,325 Pa), the unit often used as a reference of standard pressure.

History/origin: The unit, bar, was introduced by Vilhelm Bjerknes, a Norwegian meteorologist who founded modern weather forecasting. The term “bar” comes from the Greek word “baros,” which means weight.

Current use: Although the bar is a metric unit of pressure, it is not accepted within the International System of Units (SI) and is even deprecated within certain fields. The International Bureau of Weights and Measures has specified the bar as a unit that authors should have the freedom to use but has chosen not to include the bar in the list of non-SI units accepted for use with SI.

Millibars (symbol: mb) are also commonly used when referencing atmospheric air pressure, where atmospheric pressure equals 1013.25 mbar (101.325 kPa). Meteorologists and weather reporters worldwide often use this unit for convenience, since working in pascals would result in much larger values.

Pound-force per square inch(Psi)

Definition: A pound-force per square inch (symbol: psi) is an imperial and US customary unit of pressure based on avoirdupois units. It is defined as the pressure that results when a force of one pound-force is applied to a one-square-inch area. One psi is approximately 6,895 pascals (N/m²).

History/origin: Pound-force per square inch is a unit that originated in the imperial and US customary systems of units. It is based on the avoirdupois system, a system that uses weights in terms of the avoirdupois pound, which was standardized in 1959. The system is believed to have come into use in England around 1300 and was used in the international wool trade. As such, the prototype pound at the time was known as the avoirdupois wool pound.

Current use: The psi is fairly widely used to measure numerous pressures, such as tire pressure, scuba tank pressure, natural gas pipeline pressure, among others. Although the pascal is more widely used in scientific contexts, psi is more often used in everyday contexts, particularly in countries like the United States as well as others under the US customary or imperial systems of units.

Click here to read more

Quick Conversion Chart