ISO 31 (Quantities and units, International Organization for Standardization, 1992) is a superseded international standard concerning physical quantities, units of measurement, their interrelationships and their presentation.[1] It was revised and replaced by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.

Coined words

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

Related national standards

See also


  1. ^ "ISO 31-0:1992 Quantities and units — Part 0: General principles". International Organization for Standardization. Retrieved 8 May 2021.
  2. ^ Tolga, G. O. K. (2016). The importance of symbols and units in natural science. The Eurasia Proceedings of Educational and Social Sciences, 4, 165-167.
  3. ^ NIST SP811(§8.9)
  4. ^ Mills, I. (1993). Quantities, units and symbols in physical chemistry/prepared for publication by Ian Mills...[et al.]. Oxford; Boston: Blackwell Science; Boca Raton, Fla.: CRC Press [distributor].
  5. ^ Taylor, B. (1995). Guide for the use of the International System of Units (SI): the metric system. DIANE Publishing.
  6. ^ Dietrich, P. M., Streeck, C., Glamsch, S., Ehlert, C., Lippitz, A., Nutsch, A., ... & Unger, W. E. S. (2015). Quantification of silane molecules on oxidized silicon: are there options for a traceable and absolute determination?. Analytical chemistry, 87(19), 10117-10124.
  7. ^ Sertlek, H. Ö., Slabbekoorn, H., Ten Cate, C., & Ainslie, M. A. (2019). Source specific sound mapping: Spatial, temporal and spectral distribution of sound in the Dutch North Sea. Environmental pollution, 247, 1143-1157.