Litre

The (outside of Switzerland also: this) liter is a unit of volume and is symbolized by the unit symbol "l" or abbreviated as " l ".

One liter corresponds to a cubic decimeter ( dm3). A cube having an edge length of 10 cm therefore has a volume of one liter.

The liter is not part of the International System of Units ( SI), but is approved for use with the SI. Through national laws of the liter is a legal unit.

Spelling

The German unit name " liter " [li ː tɐ, also: lɪtɐ ] comes from French liter [ from MFRZ. Litron ( a measure of capacity ), mlat. litra, Greek LITRA = pounds ].

Basically, the unit characters are lowercase in the International System of Units ( SI), except that the name has been derived from the proper name of a person. In this case, the first letter of the symbol is capitalized. Accordingly, the unit symbol for liter is a small "l" as the device name " liter " was not derived from a proper name.

The big " L" was exceptionally approved by the CGPM as an alternative unit symbol for liter, to avoid confusion of the letter " l" with the digit " 1", which can occur in some fonts, and more in English and French speaking countries common. However, ISO and IEC use only the original unit symbol "l". However, IUPAC and DIN 1301-1 allow both spellings.

Occasionally, a small " l" in script ( ℓ ) is used to distinguish the unit symbol of the numeral " 1" or the uppercase letter " I " is used, the corresponding Unicode code point for the " ℓ " is U 2113.

The unit name " liter " was mainly used to DIN 1301-1. This notation, however, no longer coincided with the common linguistic use. In particular, the dictionary makes the neuter form to only second. The DIN 1301-1:2010-10 this setting has been changed from the DIN 1301-1:2002-10; Name of the unit " liter " is now defined as a male.

Prefixes

Common Decimal parts and multiples of the liter are:

History

1793, the liter was implemented in France ( in connection with the metric system ) as a new " Republican Unit" and set equal to a cubic decimeter.

1879 took over the CIPM, the French liter definition and wrote using the l (lowercase L) as a symbol before.

1901 liters of the third CGPM was redefined to that volume, containing 1 kg of pure water at the temperature of its maximum density under atmospheric pressure has ( 1013.25 hPa). The liter was about 1.000028 dm3 so large ( 1.000027 dm3 were originally specified for the conversion ). To couple light of the new task for this unit, mass and volume of a special measure of water, pure water was under these conditions, although still a density of 999.975 kg/m3, but now exactly 1.0000 kg / l

Later they put the definition laid on the water temperature of 4 ° C, the temperature of highest water density is not ( actually about 3.98 ° C). Thus pure water a slightly smaller density than 1.0000 again had kg / l

In 1964, the definition of 1793 was recovered on the 12th CGPM, since a liter is again exactly one cubic decimeter of water and has a density of 1901 as 0.999975 kg / l

In 1979, the alternative symbol L ( uppercase letter L ) was approved at the 16th CGPM per liter, at the same time expressed the desire to keep only one of the two symbols (lowercase or uppercase) in the future. Last 1990 could only be determined that it would be too early for a decision.