# Units of Measurement

Tags:

## Basic concepts

### Physical quantities

A physical quantity is a property of a physical substance that can be measured (Wiki). Examples of physical quantities are: mass, time, electric current and so on. One should not confuse the concept of physical quantity and the concept of physical (quantity) values. A physical quantity is an abstract concept, and a physical quantity value is the value of concrete phenomenon property. For example, 5 grams is a physical value of the physical quantity mass.

There are fundamental (base) physical quantities called dimensions:

• length
• time
• mass
• temperature
• electric current
• amount of substance
• luminous intensity

They are fundamental because all other quantities can be expressed via them.

### Units of measurement

An unit of measurement is a definite magnitude of a physical quantity (Wiki). One of the main purposes to use units of measurement in a computer program is to convert values of physical quantities from one unit to other ones.

The total list of units, defined in TechEditor, can be found in UNITS tab.

### Unit prefixes

A unit prefix is a specifier that indicates multiplication factor for the unit it precedes. A simple example of a prefix using is the definition of the kilogram unit kg. Here the prefix kilo ‘k’ precedes the unit gram ‘g’. It means that the magnitude of the unit must be multiplied with the value of the prefix, in this case it is 1000.

TechEditor supports many decimal and binary prefixes (see PREFIXES tab).

## How to use units in TechEditor

The rules of conversion:

• A string can contain unit symbols, prefixes, spaces, division operator sign ‘/’ and power operator sign ‘^’
• No multiplication sign allowed in a string (space symbol ‘ ‘ used instead)
• Only one division sign allowed in a string
• A prefix is not separated by spaces with the unit it belongs to
• Different units are separated by spaces (that is spaces used as multiplication operator)

Examples: MPa  N m  m s^2  kN/m

You can use units of measurement in the following document sections:

• application (MathTranslator object)
• diagram (math blocks)
• report (math or formula object)

The following example converts source units of measurement (Pa) to the target (kPa):

var  X: Double;begin
X := MathTranslator.Convert('2550 Pa', 'kPa'); // X=2.550
end;

PrefixSymbolValue
Decid1E-1
Centic1E-2
Millim1E-3
Microμ1E-6
Nanon1E-9
Picop1E-12
Femtof1E-15
Attoa1E-18
Zeptoz1E-21
Yoctoy1E-24
Hectoh1E+2
Kilok1E+3
MegaM1E+6
GigaG1E+9
TeraT1E+12
PetaP1E+15
ExaE1E+18
ZettaZ1E+21
YottaY1E+24
KibiKi1024
MebiMi1024²
GibiGi1024³
TebiTi1024⁴
PebiPi1024⁵

Unit
Symbol
Dimension
Description
Percent%1
Permille1
MetremLlength (distance)
Atomic unit of lengtha₀Llength (distance)
AngstromÅLlength (distance)
MicronμLlength (distance)
Light YearlyLlength (distance)
Mile (international)miLlength (distance)
FootftLlength (distance)
InchinLlength (distance)
YardydLlength (distance)
PointptLlength (distance)
SecondsTtime
Atomic unit of timeauTtime
MinuteminTtime
HourhTtime
KilogramkgMmass
GramgMmass
Atomic mass unitAMUMmass
Electron rest massm₀Mmass
ElectronvolteVMmass
CaratktMmass
Carat (metric)ctMmass
TonnetMmass
Kelvin°KΘtemperature
Celsius°CΘtemperature
Fahrenheit°FΘtemperature
Delisle°DeΘtemperature
Newton (temperature)°NΘtemperature
Rankine°RΘtemperature
Reaumur°ReΘtemperature
Romer°RoΘtemperature
AmpereAIelectric current
MolemolNamount of substance
CandelacdJluminous intensity
BitbΥinformation
ByteBΥinformation
NibblenibΥinformation
TrittritΥinformation
DitditΥinformation
NatnatΥinformation
Degree°Φplane angle
Arcminute'Φplane angle
Arcsecond"Φplane angle
Areaarea
Hectarehaarea
LitreLvolume
HertzHz1/Tfrequency
Revolutions per minuterpm1/Tfrequency
Light speedcL/Tspeed
Standard gravityg₀L/T²acceleration
NewtonNL M/T²force
DynedynL M/T²force
Kilogram-forcekgfL M/T²force
SthenesnL M/T²force
Ounce-forceozfL M/T²force
Pound-forcelbfL M/T²force
PoundalpdlL M/T²force
Ton-forcetnfL M/T²force
PascalPaM/L T²pressure
AtmosphereatmM/L T²pressure
BarbarM/L T²pressure
Millimetre of mercurymmHgM/L T²pressure
Millimetre of watermmH₂OM/L T²pressure
PiezepzM/L T²pressure
Pound per square footpsfM/L T²pressure
Pound per square inchpsiM/L T²pressure
TorrtorrM/L T²pressure
JouleJL² M/T²energy
ErgergL² M/T²energy
WattWL² M/T³power
StokesStL²/Tkinematic viscosity
Litre per minuteLPML³/Tflow
CoulombCT Ielectric charge
Atomic unit of chargeeT Ielectric charge
VoltVL² M/T³ Ielectric potential
AbvoltabVL² M/T³ Ielectric potential
StatvoltstatVL² M/T³ Ielectric potential
OhmOL² M/T³ I²electric resistance
WeberWbL² M/T² Imagnetic flux
TeslaTM/T² Imagnetic flux density (magnetic induction)
HenryHL² M/T² I²inductance
GaussGM/T² Imagnetic flux density (magnetic induction)
MaxwellMxL² M/T² Imagnetic flux
DebyeDL T Ielectric dipole moment
LumenlmJ Ωluminous flux
LuxlxJ Ω/L²illuminance
PhotphJ Ω/L²illuminance
FootcandlefcJ Ω/L²illuminance
Rontgen equivalent manremL²/T²dose equivalent (ionizing radiation)
RoentgenRT I/Mexposure of X-rays and gamma rays
Decibel (10)dB₁₀1corresponding to one tenth of a bel
Decibel (20)dB₂₀1corresponding to one tenth of a bel
Bellbel1
NeperNp1physical field and power quantities
Binary logarithmlog₂1
Decimal logarithmlog₁₀1
Natural logarithmlogₑ1
Decibel-milliwattsdBmL²M/T³electrical power unit in decibels
Decibel-JoulesdBJL²M/T²
Decibel-PascalsdBPaM/L T²
Decibel SPL (air)dBSPLM/L T²
Decibel-VoltsdBVL²M/T³I
1 to 10 (114)

### Users Online

No members to show currently