International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONWlE~YHAPO~HAR OPTAHbl3AL&lR fl0 CTAH~APTkl3AL&lkl@ORRGANISATION INTERNATIONALE DE NORMALISATION of SI and other Information processing - Representation units in Systems with limited Character sets Traitemen t de l’in forma tion - Reprksentation comprenant des jeux de caracthres limitb Second -w UDC Descriptors edition - des unitbs du S ystkme international et d’autres unit& dans des s ystkmes 1983-05-15 Ref No 681.3.04 : 53.081 : data processing, units of measurement, SI units, Symbols, ISO 29554983 (E) representation Price based on pages Foreword ISO (the International Organization for Standardization) is a worldwide federation of national Standards bodies (ISO member bedies) The work of developing International Standards is carried out through ISO technical committees Every member body interested in a subject for which a technical committee has been authorized has the right to be represented on that committee international organizations, governmental and non-governmental, in liaison with ISO, also take part in the werk Draft International Standards adopted by the technical the member bodies for approval before their acceptance the ISO Council committees are circulated as International Standards to by International Standard SS0 2955 was deveioped by Technical Committee ISO/TC 97, to the member bodies in Information processing s ys tems, and was circulated October 1980 It has been approved Australia Belgium Canada Cuba Finland France Germany, No member F R body expressed This second International Printed by the member edition in Switzerland bodies of the following Ireland Italy Japan Netherlands New Zealand Poland Romania disapproval : South Africa, Rep of Spain Sweden Switzerland United Kingdom USSR sf the document cancels and replaces the first edition Organkation countries for Standardkation, 1983 (i.e ISO 2955-1974) INTERNATIONAL ISO 2955-1983 (EI STANDARD of SI and other Information processing - Representation units in Systems with limited Character sets Scope and field of application This International Standard specifies two sets of repre1 l sentations, for SI units and other internationally recognized units defined in ISO 1000 along with their decimal multiples and sub-multiples formed by the use of prefixes, for use in data interchange by Systems with limited graphic Character Sets of units as listed in this International NOTE - The representations Standard are intended for use only in Systems with limited graphic Character set capabilities They are not intended to replace the international Symbols in other applications ISO 31 and ISO 1000 provide the approved international Symbols 1.3 This International Standard applies to the interchange of information among data processing Systems and associated equipment, and within message transmission Systems lt does not apply to printed matter for publication or to other forms of public information transfer In these cases, the representations of Forms I and II should be replaced by the international Symbols in ISO 31 and ISO 1000 or, if these are not available, by the unabbreviated unit names References ISO 31, Quan tities, units and s ymbols 1.2 The two sets of representations are : Form I : For Systems which have the capability to use both upper and lower case letters (double case), digits, and other graphics, at least the graphical Symbols apostrophe (7, quotation mark (‘7, hyphen (4, full stop or period 0, and solidus (/), but which not have the capability to use the Greek letters Q and ~1,the degree Symbol (O), and letters, digits and signs in the superscript Position NOTE - The ISO 646 alphabet is an example of such a Character set Form II : For Systems which have the capability to use singlecase letters only leither upper or Iower), digits, and other graphics, at least the graphical Symbols hyphen (4, full stop or period ( ), and solidus (0, but which not have the capability to use the Greek letters SZ and ~1, the degree Symbol (O), and letters, digits and signs in the superscript Position ISO 646, 7-bit coded Character in terchange ISO 1000, SI units and recommendations multiples and o f certain other units Requirements units CCITT alphabet The annex contains of units No is an example a brief description of such a Character of the International System set (SI) processing for the use of their for the representation of 3.1 Units and prefixes shall be represented appropriate columns in tables and as shown NOTE - These tables also contain and ISO 1000 Symbols 3.2 NOTE - set for information the international in the in ISO 31 In narrative (free text) data, a space Character shall be used to separate the numerical value and the unit representation, for example 10 m, m2 In formatted data, as in records, the use or non-use is defined in the format description ISO 2955-1983 (El 3.3 Multiplication of units shall be indicated between the representations of units by a full stop (.) 3.6 Negative exponents shall be indicated by a minus sign followed by the respective numeral, both together directly after the representation sf the unit; for example m - for m -3 Examples 1) Pa.s viscosity designate 2) N.m to designate Pascal newton second, unit sf dynamic metre NOTE - The use of the full stop is intended to avoid confusion could occur between m.N (metre newton) and mN (millinewton) use of N m instead of m.N is an additional safeguard against guity which : the ambi- Division of units shall be indicated either by Separation of 3.4 the numerator and the denominator by a solidus (0 or, alternatively, by expressing the denominator with a negative exponent; for example m/s or m.s- for metre per second Positive exponents shall be indicated by the respective 3.5 numerals without any further sign, directly after the representation of the unit; for example m2 for m2 3.7 Decimal multiples and sub-multiples of units shall be indicated by the combination of a prefix representation from table with the representation of any unit in table except the kilogram, kg Decimal multiples and sub-multiples for units of mass shall be based on the gram, g NOTE - lt follows that prefix repr esentations may not stand alone without a unit representation Thus, T alone sta nds for tesla not tera There shall be no separator or space between the prefix representation and the unit representation Compound prefixes shall not be used; for example, use nm (nanometre) and not mum (millimicrometre), use mg (milligram) and not ukg (microkilogram) The combination of prefix representation and unit representation forms a new unit representation which may he raised to a power with positive or negative exponent and which may be combined with other unit representations to form representations for compounds units; for example, cm2 for cm2, kN/m2 or kN.m-2 for kN/mK ISO 2955-1983 (EI TabIe Marne Base - Representations of units of unit SI units metre m m m M kilogram kg kg kg KG second S S S s ampere A A a A kelvin mole candela -Supplementary K k K mol mol MOL cd cd cd CD rad rad rad RAD sr sr sr SR SI units radian steradian Derived K mol Sf units with special names hertz Hz Hz hz newton N N n N Pascal Pa Pa Pa1 PAL - HZ joule J J i J watt W W W W coulomb C C C C volt V V V V farad F F f ohm Cl Ohm ohm S Wb S Wb tesla T henry degree H Siemens F OHM sie SIE WB T wb t H h H Cel cel CEL lumen OC Im Im Im lux IX IX IX LM LX Bq Bq bq BQ GY SV GY SV gY SV GY Weber Celsius becquerel gw sievert Other * units grade from T SV ISO 1000 (angle) wn wn GON 7s) deg ‘(s) deg mnt MNT ‘7s) I** “kJ I ** sec I SEC litre are a a are ARE g(s)* degree (angle) o(s) minute (angle) second (angle) DEG L ha har HAR min MIN hour h h hr HR daY year d d d a a ann ANN gram tonne Cl t g t Cl tne TNE bar P bar bar BAR P st st P st ST eV eV ev EV U U U AU AU asu ASU Pc Prs PRS hectare minute (time) bar Poise stokes electronvolt atomic mass unit astronomic unit Parsec “(s) indicates ** The Symbol Pc Symbol L tan is used in the right superscript be used as an alternative Position to the Symbol (in the Position D G P U of an exponent) ISO 29554983 (El Table Pref ix =actor by which the unit is multiplied - Representations International sym bol (common use Symbol) of prefixes Representation Form I (double case (Single case Iower) Form II (Single case upper) exa 10’8 E E ex EX peta 10’5 P P PE tera 10'2 T T Pe t giga mega kilo 109 G G 106 M M 103 102 k k k K h h h H 101 hecto ma T G MA da da da DA deci IO-' d d d D centi IO-2 C C C C milli IO-3 m m m M micro IO-6 U U IO-9 IJ n U nano n N pico IO-Q IO-'5 P f P femto P f atto IO-18 a a A deca F ISO 2955-1983 (E) Annex tion of the International System (This annex is based on ISO 1000 and does not form an integral m1 The name “Systeme International d’unites” (International System of Units}, with the abbreviation SI, was adopted by the Tth Conference generale des poids et mesures in 1960 This System includes a) base units, b) supplementary c) derived which together three classes of units : metre Im) kilogram second ampere (kg) is based on the in is For some of the derived SI units, special names and Symbols exist; those approved by the Conference generale des poids et mesures are listed in table lt may sometimes be advantageous to express derived units in terms of other derived units having special names; for example the SI units of electric dipole moment (As-m) is usually expressed as C-m (A) kelvin (K) (s) as units for the base quantities : length, mass, time, electric current, thermodynamic temperature, amount of substance and luminous intensity A.4 The expressions for the derived SI units are stated terms of base units; for example, the SI unit for velocity metre per second (m/s) System of SI units of Units Standard.] The SI units for plane angle and solid angle, the radian (rad) and the steradian (sr) respectively, are supplementary units in the International System of Units These units are regarded as derived units units, A.2 The international System following seven base units : part of this international A.3 units, form the coherent (SI) 0% mole (mol) candela Table Quantity Frequency A.5 Decimal multiples and sub-multiples formed by means of the prefixes (see 3.7) (cd) - Derived SI units Name of SI unit hertz with special names Symbol I Expressed in terms of basic or derived SI units Hz Hz = s-1 Forte newton N N = kg.m/sz Pressure and stress Pascal Pa Pa = N/m2 Work, energy, quantity of heat joule J J = N.m Power watt W W = J/s coulomb C C = A-s Electric potential, potential differente, electromotive forte volt V V = WIA Electric capacitance farad F F = CIV Electric resistance ohm c2 S2 = V/A Quantity of electricity Electric conductance Siemens S Weber Wb Magnetit flux density, magnetic induction tesla T T = Wb/m2 Inductance henry H H = Wb/A degree Celsius OC lumen Im Im = cdssr IX = lm/m2 Magnetit flux Celsius temperature Luminous flux Illumination s = Cl-1 Wb = V-s lOC=lK lux IX becquerel Bq Bq = s-1 Absorbed dose WY GY Gy = J/kg Dose equivalent sievert SV SV = J/kg Activity (radioactivity) of the SI units arc This page intentionally left blank