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C.5 Physical Units

CASA also recognizes physical units. They are listed in Tables C.7, C.8, and C.9.


Table C.7: Prefixes

PrefixName Value
Y (yotta) 1024
Z (zetta) 1021
E (exa) 1018
P (peta) 1015
T (tera) 1012
G (giga) 109
M (mega) 106
k (kilo) 103
h (hecto)102
da (deka) 10
d (deci) 10-1
c (centi) 10-2
m (milli) 10-3
u (micro)10-6
n (nano) 10-9
p (pico) 10-12
f (femto)10-15
a (atto) 10-18
z (zepto)10-21
y (yocto)10-24


Table C.8: SI Units

UnitName Value
$ (currency) 1 _
% (percent) 0.01
%% (permille) 0.001
A (ampere) 1 A
AE (astronomical unit)149597870659 m
AU (astronomical unit)149597870659 m
Bq (becquerel) 1 s-1
C (coulomb) 1 s A
F (farad) 1 m-2 kg-1 s4 A2
Gy (gray) 1 m2 s-2
H (henry) 1 m2 kg s-2 A-2
Hz (hertz) 1 s-1
J (joule) 1 m2 kg s-2
Jy (jansky) 10-26 kg s-2
K (kelvin) 1 K
L (litre) 0.001 m3
M0 (solar mass) 1.98891944407×1030 kg
N (newton) 1 m kg s-2
Ohm(ohm) 1 m2 kg s-3 A-2
Pa (pascal) 1 m-1 kg s-2
S (siemens) 1 m-2 kg-1 s3 A2
S0 (solar mass) 1.98891944407×1030 kg
Sv (sievert) 1 m2 s-2
T (tesla) 1 kg s-2 A-1
UA (astronomical unit)149597870659 m
V (volt) 1 m2 kg s-3 A-1
W (watt) 1 m2 kg s-3
Wb (weber) 1 m2 kg s-2 A-1
_ (undimensioned) 1 _


Table C.8: SI Units – continued

Unit Name Value
a (year) 31557600 s
arcmin(arcmin) 0.000290888208666 rad
arcsec (arcsec) 4.8481368111×10-6 rad
as (arcsec) 4.8481368111e×10-6 rad
cd (candela) 1 cd
cy (century) 3155760000 s
d (day) 86400 s
deg (degree) 0.0174532925199 rad
g (gram) 0.001 kg
h (hour) 3600 s
l (litre) 0.001 m3
lm (lumen) 1 cd sr
lx (lux) 1 m-2 cd sr
m (metre) 1 m
min (minute) 60 s
mol (mole) 1 mol
pc (parsec) 3.08567758065×1016 m
rad (radian) 1 rad
s (second) 1 s
sr (steradian)1 sr
t (tonne) 1000 kg


Table C.9: Custom Units

Unit Name Value
” (arcsec) 4.8481368111×10-6 rad
”_2 (square arcsec) 2.35044305391×10-11 sr
’ (arcmin) 0.000290888208666 rad
” (arcsec) 4.8481368111×10-6 rad
”_2 (square arcsec) 2.35044305391×10-11 sr
’_2 (square arcmin) 8.46159499408×10-8 sr
: (hour) 3600 s
:: (minute) 60 s
::: (second) 1 s
Ah (ampere hour) 3600 s A
Angstrom(angstrom) 1e-10 m
Btu (British thermal unit (Int))1055.056 m2 kg s-2
CM (metric carat) 0.0002 kg
Cal (large calorie (Int)) 4186.8 m2 kg s-2
FU (flux unit) 10-26 kg s-2
G (gauss) 0.0001 kg s-2 A-1
Gal (gal) 0.01 m s-2
Gb (gilbert) 0.795774715459 A
Mx (maxwell) 10-8 m2 kg s-2 A-1
Oe (oersted) 79.5774715459 m-1 A
R (mile) 0.000258 kg-1 s A
St (stokes) 0.0001 m2 s-1
Torr (torr) 133.322368421 m-1 kg s-2
USfl_oz (fluid ounce (US)) 2.95735295625×10-5 m3
USgal (gallon (US)) 0.003785411784 m3


Table C.9: Custom Units – continued

Unit Name Value
WU (WSRT flux unit) 5 × 10-29 kg s-2
abA (abampere) 10 A
abC (abcoulomb) 10 s A
abF (abfarad) 109 m-2 kg-1 s4 A2
abH (abhenry) 10-9 m2 kg s-2 A-2
abOhm (abohm) 10-9 m2 kg s-3 A-2
abV (abvolt) 10-8 m2 kg s-3 A-1
ac (acre) 4046.8564224 m2
arcmin_2(square arcmin) 8.46-2159499408×10-8 sr
arcsec_2 (square arcsec) 2.35044305391×10-11 sr
ata (technical atmosphere)98066.5 m-1.kg.s-2
atm (standard atmosphere)101325 m-1.kg.s-2
bar (bar) 100000 m-1.kg.s-2
beam (undefined beam area)1 _
cal (calorie (Int)) 4.1868 m2 kg s-2
count (count) 1 _
cwt (hundredweight) 50.80234544 kg
deg_2 (square degree) 0.000304617419787 sr
dyn (dyne) 10-5 m kg s-2
eV (electron volt) 1.60217733×10-19 m2 kg s-2
erg (erg) 10-7 m2 kg s-2
fl_oz (fluid ounce (Imp)) 2.84130488996×10-5 m3
ft (foot) 0.3048 m
fu (flux unit) 10-26 kg s-2
fur (furlong) 201.168 m
gal (gallon (Imp)) 0.00454608782394 m3


Table C.9: Custom Units – continued

Unit Name Value
ha (hectare) 10000 m2
hp (horsepower) 745.7 m2 kg s-3
in (inch) 0.0254 m
kn (knot (Imp)) 0.514773333333 m s-1
lambda (lambda) 1 _
lb (pound (avoirdupois))0.45359237 kg
ly (light year) 9.46073047×1015 m
mHg (metre of mercury) 133322.387415 m-1 kg s-2
mile (mile) 1609.344 m
n_mile (nautical mile (Imp)) 1853.184 m
oz (ounce (avoirdupois)) 0.028349523125 kg
pixel (pixel) 1 _
sb (stilb) 10000 m-2 cd
sq_arcmin(square arcmin) 8.46159499408×10-8 sr
sq_arcsec (square arcsec) 2.35044305391×10-11 sr
sq_deg (square degree) 0.000304617419787 sr
statA (statampere) 3.33564095198×10-10 A
statC (statcoulomb) 3.33564095198×10-10 s A
statF (statfarad) 1.11188031733×10-12 m-2 kg-1 s4 A2
statH (stathenry) 899377374000 m2 kg s-2 A-2
statOhm (statohm) 899377374000 m2 kg s-3 A-2
statV (statvolt) 299.792458 m2 kg s-3 A-1
u (atomic mass unit) 1.661×10-27 kg
yd (yard) 0.9144 m
yr (year) 31557600 s

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