Official units

Parameter

Name

Unit and conversion factor

Remarks

Activity, radioactive
(放射物活性)

becquerel
curie

1 Bq = 1/s
1 Ci = 3/7 · 10¹⁰ /s

SI unit

Dose equivalent
(等價輻射劑量)

sievert
roentgen equivalent man

1 Sv = 1 J/kg
1 rem = 10² J/kg

SI unit

Work mechanical
(機械運動)

joule
erg

1 J = 1 N · m = 1 kg · m²/S²

SI unit

Illuminance (光照度)

lux

1 lx = 1 lm/m²

SI unit

Optical power (光學功率)
Optical systems

diopter

1 dpt = 1/m

also called refractive power

Density (物質密度)

kg/m³

SI unit, usually given in g/ml or g/cm³

Rotational speed
(旋轉速度)

revolutions per minutes

1 min-1 = 1 UpM = 1/60s-1 = 1 min-1

SI unit

Pressure (壓力)

Pascal

bar

phys. atmosph.

techn. atmosph.

meter water column

mm mercury

1 Pa = 1 N/m²

1 bar = 10·5Pa

1 atm = 1.01325 · 10·5Pa

1 at = 1 kp/cm²

1 mWS = 9.790 · 10³Pa

1 mmHg = 1 Torr = 1.3332 · 10²Pa

SI unit, see also tables "Conversion factors for pressure units" and "Conversion from Anglo-Saxon units to metric units"

Energy (能量)

joule
electronvolt
calorie

1J = 1N · m = 1kg · m²/S² = 1W · s
1 eV = 1.60219 · 10¹⁹J
1 cal = 4.1868 J

SI unit

Specific energy imparted
(能量傳達)

gray
rad
rem

1 Gy = 1 J/kg
1 rd = 0.01 J/kg
1 rem = 0.01 J/kg

SI unit

Specific energy (能量比) impartation rate

1 Gy/s = 1 W/kg

SI unit

Extinction coefficient
molar
specific
(分子激發效應)

-
-

I/mol · cm
I/g · cm

also known as spectral absorptivity (DIN) or decadic absorptive power (IUPAC)

Field strength,
electrical
magnetic
(磁場強度)

volt per meter
ampere per meter
oersted

1V/m = 1m · kg/(s² · A) = 1W/(A · m)
1 A/m
1 Oe = 10²/4π · A/m

SI unit

Area (面積)

square meter

are

hectare

1 m² = 1 m · 1 m = 1 qm

1 a = 10² m²

1 ha = 100000m²

SI unit

Flux, magnetic
(磁通量)

square meter
are
hectare

1 m² = 1 m · 1 m = 1 qm
1 a = 10² m²
1 ha = 10² m²

SI unit

Flux density, electrical magnetic
(電磁通量強度)

coulomb per square meter
tesla
gauss

C/m²
1 T = 1 Wb / m² = 1 V · s/m²
1 G = 10⁴ T

SI unit

Frequency (頻率)

hertz

1 Hz = 1 S-1

SI unit for periodic processes

Speed (速度)

meter per second

kilometer per hour

m/s

1 km/h = 0.27 m/s

SI unit

Inductance, electromagnetic
(電磁感應)

henry

internat. henry

1H = 1Wb/A = 1V · s/A = 1W· s/A²
= 1 Ω · s
1 H_int = 1.00049 H

SI unit

Exposure rate (曝光率)

coulomb/kg

roentgen

C/kg

1 R = 2.58 · 10 4 C/kg

SI unit

Capacitance, electrical
(電容量)

farad

internat. farad

1 F = 1 C/V = 1 A² · s/W = 1 s/W

1 F_int = 0.99951 F

SI unit

Force (力量)

newton

pond

dyne

1 N = 1 kg · m/s²

1 P = 9.807 · 10 -3N

1 dyn = 10 -5N

SI unit

Charge, electrical (電荷)

coulomb

1 C = 1 A · s = 1 J/V

SI unit

Length (長度)

meter

micron or my

angstram

fermi

inch

1 m

1 µ = 10 · 6m

1 Å = 10 -10m

1 f = 10 -15m

1" = 25.4 mm

Basic SI unit

Power (電力)

watt

horsepower

1 W = 1 J/s

1 hp = 0.735 kW

SI unit

Conductivity, (電導度) length-related

siemens per centimeter

1 S/cm = 1 Ω^-1 · cm^-1

SI unit

Conductance (電導度)

siemens

1 S = 1 Ω^-1

SI unit

Luminance (發光強度)

candela per square meter

nit

stilb

lambert

1 cd/m²

1 nt = 1 cd/m²

1 sb = 1 cd/cm²

1 la = 1/p sb = 1/p cd/cm²

SI unit

Illumination, specific
(發光比)

lumen per square meter
phot

1 lm/m²
1 ph = 1 lm/cm²

SI unit

Luminous intensity
(發光強度)

candela
hefner-candela
internat. candela

1 cd
1 HK = 0.903 cd
1 IK = 1.019 cd

SI unit

Luminous flux (發光量)

lumen

1 lm = 1 cd · sr

SI unit

Mass (weight) (質量)

kilogram

gram

tonne

metric carat

atomic unit of mass

dalton

1 kg

1 g = 10 -3 kg

1 t = 10 3 kg

1 Kt = 0.2 g

1 u = 1 amu = 1.6605·10 -27 kg

1 Dalton = 1.6602·10 -27 kg

Basic SI unit

only for precious stones

Electric potential
(電位)

volt

internat. volt

1 V = 1 J/C = 1 W/A

Vint = 1.00034V

SI unit, also electromotive force

Amount of substance
(物質總量)

mole
molar amount
gram molecule
gram atom
gram equivalent

1 mol
1 Mol
1 Mol
1 Tom
1 Val

Basic SI unit

Proportion of substance
(物質比例)

-
-
molar fractopm

mol/mol
%

Substance concentration
(濃度)

molarity

molality

normality

1 mol/l

1 mol/kg

1 val/l

Current, electrical
(電流)

ampere

internat. ampere

1 A = 1 C/S

1 Aint = 1.000291 A

Basic SI unit

Temperature (溫度)

kelvin

degree celsius

degree kelvin

degree fahrenheit

degree rankine

degree reaumur

K = ºC + 273.15

ºC = K - 273.15

ºK = K

ºF = 1.8K - 459.4

ºRank = 1.8K

ºR = 1.25ºC

Basic SI unit

Viscosity,
dynamic (動黏度)

kinematic

-
poise
-
stokes

1 Pa · s = 1 N · s · m² = 1 kg/s · m
1 P = 0.1 Pa · s
m²/s
1 St = 1 cm²/s

SI unit

Volume
(容量)

cubic meter
litre
solid meter
spatial meter
standard cubic meter

1 m³ = 1 m · 1 m · 1 m = 1 cbm
1 l = 10³ m³ = 1 cdm
1 Fm = 1 m³
1 Rm = 1 m³
1 Nm = 1 m³

SI unit

Volumetric flow rate,
Flowrate (流量)

-
-

1 m³ /s = 10³
1 l/s = 10⁶ mm³ /s

SI unit

Quantity of heat
(熱量)

joule
calorie

1 J = 1 N · m = 1 W · s
1 cal = 4.187 J

SI unit

Resistance, electrical
(電阻)

ohm

internat. ohm
-

1 Ω = 1 V/A = 1 W/A²
= 1 kg m²/s² · A²
1 Ω_int = 1.00079 Ω
1 Ω · mm²/m

SI unit

Angle,
plane
(平面角度)

spatial (空間)

radian
round angle
grad
minute
second
gon
steradian

1 rad = 1 m/1 m = 57º17'45"
1 Vollw. = 2 π rad = 360º
1º = π/180 · rad
1' = (1/60)º
1" = (1/60)'
1 gon = π/180 · rad
1 sr = 1 m²/1m²

supplementary SI unit (plane angle = relationship between arc and radius of circle)

Time
(時間)

second
minute
hour
day

1 s = 1 sec
1 min = 60 s = 1 min
1 h = 60 min
1 d = 24 h

Basic SI unit