What are the units of measure?
A unit of measure is called a conventional reference used to measure the physical quantity of a certain object, substance or phenomenon.
This reference is established by setting a standard quantity by convention, which allows calculating the dimensions of matter.
The units of measurement allow to calculate or measure matters such as length, mass, capacity, surface, volume, temperature, time, electrical intensity or light intensity.
Units of measurement have been used since ancient times. For this reason, they have been changing over time, depending not only on human needs but also on the available technology. This implies that there have been, and still are, various systems of units of measurement.
International System of Units
Currently, the most widespread of the measurement systems is the so-called International System of Units (SI), based on the metric system.
In the International System of Units, the quantities that are quantified are:
magnitudes | Unit of measurement | Symbol |
---|---|---|
Length | meter | m |
Dough | kilogram | kg |
Weather | second | s |
Temperature | Kelvin | K |
Electric current intensity | amp | A |
amount of substance | mole | mole |
light intensity | candle | CD |
From this list, the International System of Units contemplates a set of derived units of measure. Among them, we can mention the following:
Derived quantities | unit of measurement | symbol |
---|---|---|
Volume | cubic meter / liter | m^{two} or L |
Density | kilogram per cubic meter | kg/m^{two} |
Frequency | hertz or hertz | Hz |
Strength | Newton | N |
work and energy | July | J |
Pressure | Pascal | Pa |
Power | watt or watt | W |
electrical charge | columbium | C |
Electric potential | Volt | v |
Electric resistance | ohmnium | Ω |
Absorbed radiation dose | sievert | S.v. |
See also Measurement.
SI units of length
Unit | Symbol | Equivalence |
---|---|---|
Kilometer | km | 1000m |
hectometer | hmm | 100m |
Decameter | dam | 10m |
Meter | m | 1m |
Decimeter | dm | 0.1m |
Centimeter | cm | 0.01m |
Millimeter | hmm | 0.001m |
SI Units of Area Measurement
Unit | Symbol | Equivalence |
---|---|---|
Square kilometer | km^{two} | 1,000,000m^{two} |
square hectometer | hmm^{two} | 10,000m^{two} |
square decameter | dam^{two} | 100m^{two} |
Square meter | m^{two} | 1m^{two} |
square decimeter | dm^{two} | 0.01m^{two} |
Square centimeter | cm^{two} | 0.0001m^{two} |
square millimeter | hmm^{two} | 0.000001m^{two} |
SI units of mass measurement
Unit | Symbol | Equivalence |
---|---|---|
Kilogram | kg | 1000g |
Hectogram | hg | 100g |
Decagram | dag | 10g |
Gram | g | 1g |
Decigram | dg | 0.1g |
Centigram | cg | 0.01g |
Milligram | mg | 0.001g |
SI Units of Measurement for Capacity
Unit | Symbol | Equivalence |
---|---|---|
kiloliter | kl | 1000 liters |
Hectolitre | hi | 100 liters |
Decaliter | give | 10L |
Liter | he | 1 liter |
Deciliter | dl | 0.1L |
Centiliter | cl | 0.01L |
Milliliter | ml | 0.001 l. |
SI units of volume measurement
Unit | Symbol | Equivalence |
---|---|---|
cubic kilometer | km^{3} | 1,000,000,000m^{3} |
cubic hectameter | hc^{3} | 1,000,000m^{3} |
cubic decameter | dac^{3} | 1000m^{3} |
Cubic meter | m^{3} | 1m^{3} |
cubic decimeter | dc^{3} | 0.0001m^{3} |
Cubic centimeter | cm^{3} | 0.000001m^{3} |
cubic millimeter | hmm^{3} | 0.000000001m^{3} |
Anglo-Saxon system of units of measurement
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 unitswhich applies to the magnitudes of mass, length, surface and volume.
- Length: in this model the following units of measure are used: mil, inch (in), foot (ft), yard (yd), rod (rd), chain (ch), furlong (fur), mile (mi) and league .
- Surface: 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.
- Dough: grain (gr), drachma; ounce (oz); pound (lb); stone(st); at sign; short hundredweight (US ctw); long hundredweight (UK ctw); short fourth (US qtr); long quarter (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).
- Volume for dry: pint (pt); fourth (qt); gallon (gal); peck(pk); bushel (bu).
- Volume for liquids: minimum; liquid dram (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:
- Dough
- 1 ounce (ounce) = 28.35g
- 1 pound (pound) = 453.6g
- 1 stone (stone) = 6.35kg
- Length
- 1 inch (inches) = 2.54cm
- 1 foot (feet) = 30.48cm
- 1 yard (yard) = 91.44cm
- 1 mile (thousand) = 1,609km
- Volume
- 1 pint (I painted) = 473.17ml
- 1 gallon (gallon) = 3.78 l
Units of measurement in computing
Information technology today encompasses 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 (computers), smartphones and more.
Units of measurement in computing are classified according to three categories: storage, frequency (processor, memory and graphics) and communications (speed of data transfer).
Storage units of measure
Units of measurement for computer storage use binary code as a reference.
Units | Symbol | Equivalence |
---|---|---|
Bit | 1 | |
Byte | b | 8 bit |
Kilobyte | KB | 1024 bytes |
Megabyte | MB | 1024KB |
gigabyte | UK | 1024MB |
Terabyte | TB | 1024GB |
petabyte | PB | 1024TB |
Exabyte | EB | 1024 bp |
zettabyte | ZB | 1024 EB |
yottabyte | YB | 1024 ZB |
brontobyte | bb | 1024 YB |
See also binary code.
Computer Frequency Measurement Units
The speed at 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). Currently used are megahertz or megahertz (MHz) and gigahertz or gigahertz (GHz).
Units of measurement of data transfer (computer communication)
Units of measurement in computer communication are expressed in bps, that is, bits per second. The main ones are:
Units | Symbol | Equivalence |
---|---|---|
Kilobit | Kbps | 1000bps |
megabyte | Mbps | 1,000,000 bps or 1,000 Kbps |
Gigabit | Gbps | 1,000,000,000 bps or 1000 Mbps |