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ISO 31

ISO 31

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Encyclopedia
International Standard ISO 31 (Quantities
Physical quantity
A physical quantity is a physical property of a phenomenon, body, or substance, that can be quantified by measurement.-Definition of a physical quantity:Formally, the International Vocabulary of Metrology, 3rd edition defines quantity as:...

 and units, International Organization for Standardization
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...

, 1992) was the most widely respected style guide for the use of physical quantities and units of measurement
Measurement
Measurement is the process or the result of determining the ratio of a physical quantity, such as a length, time, temperature etc., to a unit of measurement, such as the metre, second or degree Celsius...

, and formulas involving them, in scientific and educational documents worldwide . In most countries, the notations used in mathematics and science textbooks at schools and universities follow closely the guidelines given by ISO 31 . It is now superseded by the harmonized ISO/IEC 80000
ISO/IEC 80000
International standard ISO 80000 or IEC 80000—depending on which of the two international standards bodies International Organization for Standardization and International Electrotechnical Commission is in charge of each respective part—is a style guide for the use of physical quantities and units...

 standard.

Parts


The standard comes in 14 parts:
  • ISO 31-0
    ISO 31-0
    ISO 31-0 is the introductory part of international standard ISO 31 on quantities and units. It provides guidelines for using physical quantities, quantity and unit symbols, and coherent unit systems, especially the SI...

    : General principles
  • ISO 31-1
    ISO 31-1
    ISO 31-1 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to space and time.Its definitions include:Annex A of ISO 31-1 lists units of space and time based on the foot, pound and second...

    : Space
    Space
    Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum...

     and time
    Time
    Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....

     (replaced by ISO/IEC 80000
    ISO/IEC 80000
    International standard ISO 80000 or IEC 80000—depending on which of the two international standards bodies International Organization for Standardization and International Electrotechnical Commission is in charge of each respective part—is a style guide for the use of physical quantities and units...

    -3:2007)
  • ISO 31-2
    ISO 31-2
    ISO 31-2 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to periodic and related phenomena.Its definitions include:...

    : Periodic and related phenomena (replaced by ISO/IEC 80000
    ISO/IEC 80000
    International standard ISO 80000 or IEC 80000—depending on which of the two international standards bodies International Organization for Standardization and International Electrotechnical Commission is in charge of each respective part—is a style guide for the use of physical quantities and units...

    -3:2007)
  • ISO 31-3
    ISO 31-3
    ISO 31-3 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to mechanics.Its definitions include:...

    : Mechanics (replaced by ISO/IEC 80000
    ISO/IEC 80000
    International standard ISO 80000 or IEC 80000—depending on which of the two international standards bodies International Organization for Standardization and International Electrotechnical Commission is in charge of each respective part—is a style guide for the use of physical quantities and units...

    -4:2006)
  • ISO 31-4
    ISO 31-4
    ISO 31-4 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to heat.Its definitions include:...

    : Heat
    Heat
    In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...

     (replaced by ISO/IEC 80000
    ISO/IEC 80000
    International standard ISO 80000 or IEC 80000—depending on which of the two international standards bodies International Organization for Standardization and International Electrotechnical Commission is in charge of each respective part—is a style guide for the use of physical quantities and units...

    -5:2007)
  • ISO 31-5
    ISO 31-5
    ISO 31-5 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to electricity and magnetism.Some of its definitions are below, with values taken from :...

    : Electricity
    Electricity
    Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

     and magnetism
    Magnetism
    Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...

  • ISO 31-6
    ISO 31-6
    ISO 31-6 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to light and related electromagnetic radiations.Its definitions include:...

    : Light
    Light
    Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...

     and related electromagnetic radiation
    Electromagnetic radiation
    Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...

    s
  • ISO 31-7
    ISO 31-7
    ISO 31-7 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to acoustics.Its definitions include:...

    : Acoustics
    Acoustics
    Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics...

     (replaced by ISO/IEC 80000
    ISO/IEC 80000
    International standard ISO 80000 or IEC 80000—depending on which of the two international standards bodies International Organization for Standardization and International Electrotechnical Commission is in charge of each respective part—is a style guide for the use of physical quantities and units...

    -8:2007)
  • ISO 31-8
    ISO 31-8
    ISO 31-8 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to physical chemistry and molecular physics.-Quantities and units:-Notes:...

    : Physical chemistry
    Chemistry
    Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

     and molecular physics
    Molecular physics
    Molecular physics is the study of the physical properties of molecules, the chemical bonds between atoms as well as the molecular dynamics. Its most important experimental techniques are the various types of spectroscopy...

  • ISO 31-9
    ISO 31-9
    ISO 31-9 gives name, symbol and definition for 51 quantities and units of atomic and nuclear physics. Where appropriate, conversion factors are also given...

    : Atomic and nuclear physics
    Nuclear physics
    Nuclear physics is the field of physics that studies the building blocks and interactions of atomic nuclei. The most commonly known applications of nuclear physics are nuclear power generation and nuclear weapons technology, but the research has provided application in many fields, including those...

  • ISO 31-10
    ISO 31-10
    ISO 31-10 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to nuclear reactions and ionizing radiations. It gives names and symbols for 70 quantities and units. Where appropriate, conversion factors are also given.Its definitions include:...

    : Nuclear reaction
    Nuclear reaction
    In nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or else a nucleus of an atom and a subatomic particle from outside the atom, collide to produce products different from the initial particles...

    s and ionizing radiation
    Ionizing radiation
    Ionizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons...

    s
  • ISO 31-11
    ISO 31-11
    ISO 31-11 was the part of international standard ISO 31 that defines mathematical signs and symbols for use in physical sciences and technology...

    : Mathematical signs and symbol
    Symbol
    A symbol is something which represents an idea, a physical entity or a process but is distinct from it. The purpose of a symbol is to communicate meaning. For example, a red octagon may be a symbol for "STOP". On a map, a picture of a tent might represent a campsite. Numerals are symbols for...

    s for use in the physical sciences and technology
    Technology
    Technology is the making, usage, and knowledge of tools, machines, techniques, crafts, systems or methods of organization in order to solve a problem or perform a specific function. It can also refer to the collection of such tools, machinery, and procedures. The word technology comes ;...

  • ISO 31-12
    ISO 31-12
    ISO 31-12 gives name, symbol and definition for 25 selected characteristic numbers used for the description of transport phenomena.*http://www.iso.org/iso/catalogue_detail.htm?csnumber=3655...

    : Characteristic number
    Number
    A number is a mathematical object used to count and measure. In mathematics, the definition of number has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers....

    s
  • ISO 31-13
    ISO 31-13
    ISO 31-13 gives name, symbol and definition for 62 quantities and units of solid state physics. Where appropriate, conversion factors are also given....

    : Solid state physics


A second international standard on quantities and units was IEC 60027
IEC 60027
IEC 60027 is the International Electrotechnical Commission's standard on Letter symbols to be used in electrical technology...

 . 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, http://www.iec.ch/zone/si/si_present.htm) to integrate both standards into a joint standard ISO/IEC 80000 - Quantities and Units
ISO/IEC 80000
International standard ISO 80000 or IEC 80000—depending on which of the two international standards bodies International Organization for Standardization and International Electrotechnical Commission is in charge of each respective part—is a style guide for the use of physical 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
ISO 31-0
ISO 31-0 is the introductory part of international standard ISO 31 on quantities and units. It provides guidelines for using physical quantities, quantity and unit symbols, and coherent unit systems, especially the SI...

 introduced several new words into the English language
English language
English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

 that are direct spelling-calques from the French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

. The intention was that these words be used in scientific papers for the sake of convenience and clarity.
New phrase Existing phrase Technical meaning
massic specific a quantity divided by its associated mass
volumic [volumic] density a quantity divided by its associated volume
areic surface density a quantity divided by its associated area
lineic linear density a quantity divided by its associated length

Related national standards

  • 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
    Si
    Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...

     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
    Si
    Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...

     – 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
    ISO 31-0
    ISO 31-0 is the introductory part of international standard ISO 31 on quantities and units. It provides guidelines for using physical quantities, quantity and unit symbols, and coherent unit systems, especially the SI...

  • IUPAP – much of the material in ISO 31 comes originally from Document IUPAP-25 of the Commission for Symbols, Units and Nomenclature (SUN Commission) 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 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
    IEC 60027
    IEC 60027 is the International Electrotechnical Commission's standard on Letter symbols to be used in electrical technology...

     Letter symbols to be used in electrical technology
  • ISO 1000
    ISO 1000
    International standard ISO 1000 is the ISO standard describing the International System of Units ....

    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)

External links