Convert between bars and millibars and other major units of pressure.

A unit of pressure, = 106 dynes per square centimeter = 105 pascals. The bar is not an SI unit, but continued use, temporarily, of the millibar in meteorology has been sanctioned. The microbar (1 dyne per square centimeter) is often used in calibrating microphones and loudspeakers.

Symbol, bar. In SI, the symbol for the millibar is mbar, but the symbol mb is usually used in meteorology.

According to the current national standard in the United States¹, the bar is not to be used. Kilopascals should be used instead. (1 millibar = 1 hectopascal.)

1. IEEE/ASTM SI 10-02.
American National Standard for Use of the International System of Units (SI): The Modern Metric System.
New York: IEEE, 30 December 2002.

See Section 3.3.3.


Prof. Gopal noted that the decline in use of the torr and mbar in favour of the SI unit pascal has taken about sixty years.

Bureau International des Poids et Mesures.
Comité International des Poids et Mesures.
Procès-verbaux de la 87e session.
Report of the 87th Meeting, 1998.

Tome 66.
Sèvres: BIPM, 1999.
Page 182.


Convert to and from dynes per sq. centimeter to other major units of pressure

In the centimeter-gram-second absolute system of units, the unit of pressure = 1 dyne per square centimeter.


In France, a term for 1,000 kilograms, used in the early days of the metric system. By the mid-19th century, it had been replaced by millier and tonneau in France.¹ Currently tonneau refers to a cask smaller than a tonne.

1. Doursther, page 45. 

2. Latimer Clark.
A Dictionary of Metric and Other Useful Measures.
London: E & F. N. Spon, 1891.


In India, 19th century, “Weight by which cotton is weighed, equal to 20 Dharies of 48 Sers each, or to 960 Sers.”¹

1. H. H. Wilson.
A Glossary of Judicial and Revenue Terms, and of Useful Words Occurring in Official Documents Relating to the Administration of the Government of British India, from the Arabic, Persian, Hindustání, Sanskrit, Hindí, Bengálí, Uṛiya, Maráṭhi, Guzaráthí, Telugu, Karnáta, Tamil, Malayálam, and other Languages.
London: W. H. Allen and Co., 1855.

Page 571. Wilson marks this definition as questionable. The language is Guzaráthí.

home | units index | search |  contact drawing of envelope |  contributors | 
help | privacy | terms of use