Contents 1 Contents list 2 Names, symbols and definitions 2.1 Space and time 2.1.1 Space 2.1.1.1 Units of length, area and volume 2.1.1.2 Units of angle 2.1.1.3 Quantities 2.1.2 Time 2.1.2.1 Units of time, speed and acceleration 2.1.2.2 Quantities 2.2 Logarithmic quantities and units 3 Annex A (informative) 4 Annex B (informative) 5 Annex C (informative) 6 References

Contents list The standard is divided into the following chapters: Foreword Introduction Scope Normative references Names, symbols and definitions Annex A (informative) Units in the CGS system with special names Annex B (informative) Units based on the foot, pound, second, and some other related units Annex C (informative) Other non-SI units given for information, especially regarding the conversion factors

Names, symbols and definitions Space and time Space ISO 80000-3:2006 assigns names and symbols to quantities and units of space and time, and defines these quantities and units. For example, Units of length, area and volume metre (symbol m): "length of the path travelled by light in vacuum during a time interval of 1/(299 792 458) of a second." Other units of distance defined by the standard are the ångström (symbol Å) (10−10 m) and the nautical mile (1852 m). No symbol is given for the nautical mile. The are (symbol a) is a unit of area equal to 100 square metres. The litre (symbol L or l) is a unit of volume equal to 10−3 m3. Units of angle radian degree of arc: π/180 radians minute of arc: 1/60 degrees of arc second of arc: 1/60 minutes of arc gon: π/200 rad Quantities curvature: χ = 1/ρ, where ρ = radius of curvature area volume angle: α = s/r, where s = length of arc of a circle and r = radius of the circle solid angle Time ISO 80000-3:2006 assigns names and symbols to quantities and units of space and time, and defines these quantities and units. For example, Units of time, speed and acceleration second (symbol s): "duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom" Other units of time defined by the standard include the minute (1 min = 60 s), the hour (1 h = 60 min) and the day (1 d = 24 h). The year (1 a = 365 d or 366 d) is defined in an informative annex. knot (symbol kn): one nautical mile per hour = 1852/3600 m/s ≈ 0.514 444 m/s. Quantities The standard acceleration of free fall is 9.806 65 m/s2. Logarithmic quantities and units Units of level defined by ISO 80000-3:2006 are: neper: 1 Np = ln(e) = 1 bel: 1 B = ln(√10) Np ≈ 1.1512925464970228420089957273422 Np decibel: 1 dB = 0.1 B

Annex A (informative) The following CGS units are deprecated: The gal (CGS unit of acceleration, equal to 1 cm/s2)

Annex B (informative) The following non-SI units are deprecated by the standard: The inch (Imperial unit of distance, equal to 25.4 mm) The foot (Imperial unit of distance, equal to 12 inches) The yard (Imperial unit of distance, equal to 3 feet) The mile (Imperial unit of distance, equal to 1760 yards) The acre (Imperial unit of area, equal to 4840 square yards)

Annex C (informative) The following non-SI units are given for conversion. They are not deprecated by the standard: Units of distance: light year (the distance travelled in one year by light in vacuum; abbreviation l.y.; 1 l.y. ≈ 9.460 730 × 1015 m), astronomical unit (the mean distance of the Earth from the Sun, 1 ua ≈ 1.495 978 706 91(30) × 1011 m), parsec (the distance at which 1 ua subtends an angle of 1″ (second of arc); 1 pc ≈ 206 264.8 ua ≈ 30.856 78 × 1015 m) Units of time: year (a), equal to either 365 days or 366 days

References ^ "ISO 80000-3:2006". International Organization for Standardization. Retrieved 20 July 2013.  v t e ISO standards by standard number List of ISO standards / ISO romanizations / IEC standards 1–9999 1 2 3 4 5 6 7 9 16 31 -0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 128 216 217 226 228 233 259 269 302 306 428 518 519 639 -1 -2 -3 -5 -6 646 690 732 764 843 898 965 1000 1004 1007 1073-1 1413 1538 1745 1989 2014 2015 2022 2047 2108 2145 2146 2240 2281 2709 2711 2788 2848 2852 3029 3103 3166 -1 -2 -3 3297 3307 3602 3864 3901 3977 4031 4157 4217 4909 5218 5428 5775 5776 5800 5964 6166 6344 6346 6385 6425 6429 6438 6523 6709 7001 7002 7098 7185 7200 7498 7736 7810 7811 7812 7813 7816 8000 8178 8217 8571 8583 8601 8632 8652 8691 8807 8820-5 8859 -1 -2 -3 -4 -5 -6 -7 -8 -8-I -9 -10 -11 -12 -13 -14 -15 -16 8879 9000/9001 9075 9126 9293 9241 9362 9407 9506 9529 9564 9594 9660 9897 9899 9945 9984 9985 9995 10000–19999 10005 10006 10007 10116 10118-3 10160 10161 10165 10179 10206 10218 10303 -11 -21 -22 -28 -238 10383 10487 10585 10589 10646 10664 10746 10861 10957 10962 10967 11073 11170 11179 11404 11544 11783 11784 11785 11801 11898 11940 (-2) 11941 11941 (TR) 11992 12006 12182 12207 12234-2 13211 -1 -2 13216 13250 13399 13406-2 13450 13485 13490 13567 13568 13584 13616 14000 14031 14224 14289 14396 14443 14496 -2 -3 -6 -10 -11 -12 -14 -17 -20 14644 14649 14651 14698 14750 14764 14882 14971 15022 15189 15288 15291 15292 15398 15408 15444 -3 15445 15438 15504 15511 15686 15693 15706 -2 15707 15897 15919 15924 15926 15926 WIP 15930 16023 16262 16612-2 16750 16949 (TS) 17024 17025 17100 17203 17369 17442 17799 18000 18004 18014 18245 18629 18916 19005 19011 19092 (-1 -2) 19114 19115 19125 19136 19439 19500 19501 19502 19503 19505 19506 19507 19508 19509 19510 19600:2014 19752 19757 19770 19775-1 19794-5 19831 20000+ 20000 20022 20121 20400 21000 21047 21500 21827:2002 22000 23270 23271 23360 24517 24613 24617 24707 25178 25964 26000 26300 26324 27000 series 27000 27001 27002 27006 27729 28000 29110 29148 29199-2 29500 30170 31000 32000 38500 40500 42010 55000 80000 -1 -2 -3 Category Retrieved from "https://en.wikipedia.org/w/index.php?title=ISO_80000-3&oldid=806606735" Categories: ISO/IEC 80000