Meaning of units of measurement (what they are, concept and definition)

What are Units of measure:

A conventional reference that is used to measure the physical magnitude of a certain object, substance, or phenomenon is called a unit of measurement.

This reference is established by setting a standard quantity by convention, which allows calculating the dimensions of matter.

Units of measure allow you to calculate or measure issues such as length, mass, capacity, area, volume, temperature, time, electrical intensity, or light intensity.

Units of measurement have been used since ancient times. For this reason, they have varied over time, depending not only on human needs but also on available technology. This implies that various systems of units of measurement have existed, and still exist.

International System of Units

Currently, the most widespread of the measurement systems is the so-called International System of Units (SI), based on the decimal metric system.

In the International System of Units, the quantities that are quantified are:

Magnitudes	Unit of measurement	Symbol
Length	meter	m
Mass	kilogram	Kg
Weather	second	s
Temperature	Kelvin	K
Electric current intensity	amp	TO
Amount of substance	mole	mole
Luminous intensity	candle	CD

From this list, the International System of Units contemplates a set of derived measurement units. Among them, we can mention the following:

Derived quantities	unit of measurement	symbol
Volume	cubic meter / liter	m 2 o L
Density	kilogram per cubic meter	kg / m 2
Frequency	Hertz or hertz	Hz
Force	Newton	N
Work and energy	July	J
Pressure	Pascal	Pa
Power	Watt or watt	W
Electric charge	Columbium	C
Electric potential	Volt	V
Electric resistance	Ohm	Ω
Absorbed radiation dose	Sievert	Sv

SI units of length measurement

Unit	Symbol	Equivalence
Kilometer	km	1000 m
Hectometer	hm	100 m
Decameter	dam	10 m
Meter	m	1 m
Decimeter	dm	0.1m
Centimeter	cm	0.01 m
Millimeter	mm	0.001 m

SI units of measurement

Unit	Symbol	Equivalence
Square kilometer	km 2	1,000,000 m 2
Square hectometer	hm 2	10,000 m 2
Square dekameter	dam 2	100 m 2
Square meter	m 2	1 m 2
Square decimeter	dm 2	0.01 m 2
Square centimeter	cm 2	0.0001 m 2
Square millimeter	mm 2	0.000001 m 2

Units of measurement of mass in the SI

Unit	Symbol	Equivalence
Kilogram	kg	1000 g
Hectogram	hg	100 g
Decagram	dag	10 g
Gram	g	1 g
Decigram	dg	0.1 g
Centigram	cg	0.01 g
Milligram	mg	0.001 g

Units of measure of capacity in the SI

Unit	Symbol	Equivalence
Kiloliter	kl	1000 l.
Hectolitre	hl	100 l.
Decaliter	dal	10 l.
Liter	l	1 l.
Deciliter	dl	0.1 l.
Centiliter	cl	0.01 l.
Milliliter	ml	0.001 l.

Units of measure of volume in the SI

Unit	Symbol	Equivalence
Cubic kilometer	km 3	1,000,000,000 m 3
Cubic hectometer	hc 3	1,000,000 m 3
Cubic dekameter	dac 3	1 000 m 3
Cubic meter	m 3	1 m 3
Cubic decimeter	dc 3	0.0001 m 3
Cubic centimeter	cm 3	0.000001 m 3
Cubic millimeter	mm 3	0.000000001 m 3

Anglo-Saxon system of measurement units

To date, the only countries that have not adopted the International System of Units are the United States, Burma and Liberia.

In these countries the so-called Anglo-Saxon model of units still applies, which applies to the magnitudes of mass, length, area and volume.

• Length: In this model the following units of measurement are used: thousand, inch (in), foot (ft), yard (yd), rod (rd), chain (ch), furlong (fur), mile (mi) and league. Area: square foot (sq ft or ft²); square yard (sq yd or yd²); square rod (sq rd or '' rd²); rood; acre (ac); homestead; square mile (sq mi or mi²) and square league. Mass: grain (gr), drachma; ounce (oz); pound (lb); stone (st); at; short quintal (US ctw); long quintal (UK ctw); short quarter (US qtr); quarter long (UK qtr); short ton (US ton); long ton (UK ton). Volume:
  • Volume for solids: cubic inch (in³ or cu in); cubic foot (ft³ or cu ft); cubic yard (yd³ or cu yd); acre-foot; cubic mile (mi³ or cu mi). Dry volume: pint (pt); fourth (qt); gallon (gal); peck (pk); bushel (bu). Volume for liquids: minim; liquid drachma (fl dr); fluid ounce (fl oz); gill; pint (pt); fourth (qt); gallon (gal) and barrel.

Equivalences between the Anglo-Saxon model and the SI

To better understand the equivalences between both systems, let's follow the following scheme where the most used units are expressed:

• Mass
  • 1 ounce ( ounce ) = 28.35 g1 pound ( pound ) = 453.6 g1 stone ( stone ) = 6.35 kg
  Length
  • 1 inch ( inch ) = 2.54 cm1 foot ( foot ) = 30.48 cm1 yard ( yard ) = 91.44 cm1 mile ( mile ) = 1.609 km
  Volume
  • 1 pint ( pint ) = 473.17 ml 1 gallon ( gallon ) = 3.78 l

Units of measurement in computing

Computing today covers all areas of production and social communication. Therefore, it is convenient to know the current units of measurement, which apply to all kinds of computing devices such as computers, smartphones and more.

The units of measurement in computing are classified into three categories: storage, frequency (processor, memory and graphics) and communications (speed of data transfer).

Storage units of measure

The units of measurement for computer storage use the binary code as a reference.

Units	Symbol	Equivalence
Bit		one
Byte	b	8 bit
Kilobyte	KB	1024 bytes
Megabyte	MB	1024 KB
Gigabyte	GB	1024 MB
Terabyte	TB	1024 GB
Petabyte	PB	1024 TB
Exabyte	EB	1024 PB
Zetabyte	ZB	1024 EB
Yottabyte	Yb	1024 ZB
Brontobyte	BB	1024 YB

Computer frequency measurement units

The speed in which data is processed in computing, whether in reference to the processor, graphics or memory, among other elements, is measured in Hertz or hertz (hz). At present the used megahertz or megahertz (MHz) and gigahertz or gigahertz (GHz).

Data transfer measurement units (computer communication)

The units of measurement in computer communication are expressed in bps, that is, bits per second. The main ones are:

Units	Symbol	Equivalence
Kilobit	Kbps	1,000 bps
Megabit	Mbps	1,000,000 bps or 1,000 Kbps
Gigabit	Gbps	1,000,000,000 bps or 1,000 Mbps