ISO 31 (Quantities and units, International Organization for Standardization, 1992) is a superseded international standard concerning physical quantities, units of measurement, their interrelationships and their presentation. It was revised and replaced by ISO/IEC 80000.

Parts

The standard comes in 14 parts:

  • ISO 31-0: General principles (replaced by ISO/IEC 80000-1:2009)
  • ISO 31-1: Space and time (replaced by ISO/IEC 80000-3:2007)
  • ISO 31-2: Periodic and related phenomena (replaced by ISO/IEC 80000-3:2007)
  • ISO 31-3: Mechanics (replaced by ISO/IEC 80000-4:2006)
  • ISO 31-4: Heat (replaced by ISO/IEC 80000-5)
  • ISO 31-5: Electricity and magnetism (replaced by ISO/IEC 80000-6)
  • ISO 31-6: Light and related electromagnetic radiations (replaced by ISO/IEC 80000-7)
  • ISO 31-7: Acoustics (replaced by ISO/IEC 80000-8:2007)
  • ISO 31-8: Physical chemistry and molecular physics (replaced by ISO/IEC 80000-9)
  • ISO 31-9: Atomic and nuclear physics (replaced by ISO/IEC 80000-10)
  • ISO 31-10: Nuclear reactions and ionizing radiations (replaced by ISO/IEC 80000-10)
  • ISO 31-11: Mathematical signs and symbols for use in the physical sciences and technology (replaced by ISO 80000-2:2009)
  • ISO 31-12: Characteristic numbers (replaced by ISO/IEC 80000-11)
  • ISO 31-13: Solid state physics (replaced by ISO/IEC 80000-12)

A second international standard on quantities and units was IEC 60027. The ISO 31 and IEC 60027 Standards were revised by the two standardization organizations in collaboration ([http://www.bipm.org/en/si/si_brochure/chapter1/1-2.html], [https://web.archive.org/web/20090301164428/http://www.iec.ch/zone/si/si_present.htm]) 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. Some of these words have been used in scientific literature.

{| class="wikitable"

|-

! 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

|}

  • Canada: CAN/CSA-Z234-1-89 Canadian Metric Practice Guide (covers some aspects of ISO 31-0, but is not a comprehensive list of physical quantities comparable to ISO 31)
  • United States: There are several national SI guidance documents, such as NIST SP 811, NIST SP 330, NIST SP 814, IEEE/ASTM SI 10, SAE J916. These cover many aspects of the ISO 31-0 standard, but lack the comprehensive list of quantities and units defined in the remaining parts of ISO 31.

See also

  • SI – the international system of units
  • BIPM – publishes freely available information on SI units [http://www.bipm.org/en/si/si_brochure/], which overlaps with some of the material covered in ISO 31-0
  • IUPAP – much of the material in ISO 31 comes originally from Document IUPAP-25 of the Commission for Symbols, Units and Nomenclature (SUN Commission) [https://web.archive.org/web/20050906064148/http://www.physics.umanitoba.ca/IUPAP/C2.html] of the International Union of Pure and Applied Physics
  • IUPAC – some of the material in ISO 31 originates from the Interdivisional Committee on Terminology, Nomenclature and Symbols [https://web.archive.org/web/20050828172951/http://www.iupac.org/standing/ictns.html] of the International Union of Pure and Applied Chemistry
  • Quantities, Units and Symbols in Physical Chemistry – this IUPAC "Green Book" covers many ISO 31 definitions
  • IEC 60027 Letter symbols to be used in electrical technology
  • ISO 1000 SI Units and Recommendations for the use of their multiples and of certain other units (bundled with ISO 31 as the ISO Standards Handbook – Quantities and units)

Notes

References

  • (contains both ISO 31 and ISO 1000)
  • ISO TC12 standards – Quantities, units, symbols, conversion factors