ISO 31 (Quantities and units, International Organization for Standardization, 1992) is a superseded international standard concerning physical quantities, units of measurement, their interrelationships and their presentation.[1] It was revised and replaced by ISO/IEC 80000.
The standard comes in 14 parts:
A second international standard on quantities and units was IEC 60027.[2] The ISO 31 and IEC 60027 Standards were revised by the two standardization organizations in collaboration ([1], [2]) to integrate both standards into a joint standard ISO/IEC 80000 - Quantities and Units in which the quantities and equations used with SI are to be referred as the International System of Quantities (ISQ). ISO/IEC 80000 supersedes both ISO 31 and part of IEC 60027.
ISO 31-0 introduced several new words into the English language that are direct spelling-calques from the French.[3] Some of these words have been used in scientific literature.[4][5][6][7]
| New phrase | Existing phrase | Technical meaning |
|---|---|---|
| massic <quantity> | specific <quantity> | a quantity divided by its associated mass |
| volumic <quantity> | [volumic] <quantity> density | a quantity divided by its associated volume |
| areic <quantity> | surface <quantity> density | a quantity divided by its associated area |
| lineic <quantity> | linear <quantity> density | a quantity divided by its associated length |
