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Review of the metric system (and how to convert)
Review of the metric system (and how to convert)
Published: 2013/07/14
Channel: Nancy Foote
Understanding The Metric System
Understanding The Metric System
Published: 2013/02/20
Channel: SmithMathAcademy
Metric & Standard Measurement Systems
Metric & Standard Measurement Systems
Published: 2007/08/22
Channel: NASAconnect
Units of Measure: Scientific Measurements & SI System
Units of Measure: Scientific Measurements & SI System
Published: 2016/03/05
Channel: ProEdify
Why the metric system matters - Matt Anticole
Why the metric system matters - Matt Anticole
Published: 2016/07/21
Channel: TED-Ed
History of Measurement
History of Measurement
Published: 2014/04/18
Channel: Brittany Granquist
Metric System Conversions Song | Measurement by NUMBEROCK
Metric System Conversions Song | Measurement by NUMBEROCK
Published: 2015/10/29
Channel: NUMBEROCK Math Songs
Measurement Mystery: Crash Course Kids #9.2
Measurement Mystery: Crash Course Kids #9.2
Published: 2015/05/07
Channel: Crash Course Kids
Basic Math: Lesson 7 - Units of Measurement
Basic Math: Lesson 7 - Units of Measurement
Published: 2008/12/19
Channel: The Video Math Tutor
Scientific Units the SI System and Metric Units - Chemistry
Scientific Units the SI System and Metric Units - Chemistry
Published: 2011/10/10
Channel: Mr. Causey
What is Measurement System Analysis? - Measurement Error, Bias, Linearity and Stability
What is Measurement System Analysis? - Measurement Error, Bias, Linearity and Stability
Published: 2012/04/25
Channel: GageRandR
10/20 Measurement (1/2)
10/20 Measurement (1/2)
Published: 2017/03/20
Channel: PSOM MCTC
Lecture - 3 Measurement Systems Characteristics
Lecture - 3 Measurement Systems Characteristics
Published: 2008/05/19
Channel: nptelhrd
Unit Conversion & Significant Figures: Crash Course Chemistry #2
Unit Conversion & Significant Figures: Crash Course Chemistry #2
Published: 2013/02/19
Channel: CrashCourse
SI Units and Metric Conversions
SI Units and Metric Conversions
Published: 2014/09/07
Channel: Nicole Stratton
Metric System Review - Unit Conversion Measurement Tables & Dimensional Analysis
Metric System Review - Unit Conversion Measurement Tables & Dimensional Analysis
Published: 2016/02/07
Channel: The Organic Chemistry Tutor
Ounces (oz), Pounds (lbs) and Tons Song ★ Weights and Measurement For Kids ★ Math Video by NUMBEROCK
Ounces (oz), Pounds (lbs) and Tons Song ★ Weights and Measurement For Kids ★ Math Video by NUMBEROCK
Published: 2015/08/11
Channel: NUMBEROCK Math Songs
Measurement System Analysis
Measurement System Analysis
Published: 2012/01/02
Channel: nptelhrd
Inches, Feet and Yards Song ⋆ Measurement by NUMBEROCK
Inches, Feet and Yards Song ⋆ Measurement by NUMBEROCK
Published: 2015/09/17
Channel: NUMBEROCK Math Songs
Drug Calculations - converting between systems of measurement 105
Drug Calculations - converting between systems of measurement 105
Published: 2014/03/17
Channel: HCCMathHelp
Six Sigma: Measurement System Evaluation - Part 1 - Introduction
Six Sigma: Measurement System Evaluation - Part 1 - Introduction
Published: 2013/11/30
Channel: ProfessorEaston
Keithley 4200-SCS Lecture 1: Introduction - System Overview - DC I-V Source Measurement
Keithley 4200-SCS Lecture 1: Introduction - System Overview - DC I-V Source Measurement
Published: 2011/02/04
Channel: nanohubtechtalks
THE U.S. MEASUREMENT SYSTEM IN 4 MINUTES!!! (Part 1 - Length)
THE U.S. MEASUREMENT SYSTEM IN 4 MINUTES!!! (Part 1 - Length)
Published: 2017/08/22
Channel: LARN - Learn with Lara
XI-2.01. Units and Measurement part-1(2014), Pradeep Kshetrapal Physics
XI-2.01. Units and Measurement part-1(2014), Pradeep Kshetrapal Physics
Published: 2014/05/25
Channel: Pradeep Kshetrapal
Measurement Systems: Metric vs. English
Measurement Systems: Metric vs. English
Published: 2015/07/03
Channel: Vienna Vance
US Measurement System - May be best to watch at 1.5x speed
US Measurement System - May be best to watch at 1.5x speed
Published: 2013/12/15
Channel: CalHighEngineering
Converting metric units of measurement
Converting metric units of measurement
Published: 2010/10/08
Channel: Mathademics
Angle and its measurement : sexagesimal, circular, centisimal systems
Angle and its measurement : sexagesimal, circular, centisimal systems
Published: 2015/09/17
Channel: Disha EduTube
Review of a dress made using my 10-measurement cutting system. How to adjust the basic pattern.
Review of a dress made using my 10-measurement cutting system. How to adjust the basic pattern.
Published: 2017/08/09
Channel: Paukshte Fashion Workshop
Measurement system in Mechatronics : Mechatronics Lectures
Measurement system in Mechatronics : Mechatronics Lectures
Published: 2016/12/30
Channel: engineering lectures.org
MSA | Measurement System Analysis | Gage R & R | Total Variation
MSA | Measurement System Analysis | Gage R & R | Total Variation
Published: 2016/03/26
Channel: Shakehand with Life
Image Dimension Measurement System
Image Dimension Measurement System
Published: 2013/03/27
Channel: KeyenceUSA
Complexity Made Simple  - Measurement System Analysis (SPC)
Complexity Made Simple - Measurement System Analysis (SPC)
Published: 2016/12/20
Channel: Paul Allen
Real World: US Standards of Measurement v. Decimal System
Real World: US Standards of Measurement v. Decimal System
Published: 2008/09/03
Channel: NASAeClips
Why America still uses Fahrenheit
Why America still uses Fahrenheit
Published: 2017/08/29
Channel: Vox
How to Calculate your BMI (US Customary system of measurement)
How to Calculate your BMI (US Customary system of measurement)
Published: 2009/04/30
Channel: CYWHBoston
Metric Measurement: Capacity
Metric Measurement: Capacity
Published: 2011/06/25
Channel: MaestraD
What is Centesimal system of measurement?
What is Centesimal system of measurement?
Published: 2014/02/26
Channel: AppuSeriesAcademy
Introduction to Measurement and the Metric System: Power Point with Commentary
Introduction to Measurement and the Metric System: Power Point with Commentary
Published: 2013/06/21
Channel: teachmechemistry
Projectile Orientation Measurement System
Projectile Orientation Measurement System
Published: 2017/02/15
Channel: Image Systems
Static and Dynamic characteristics of Measurement System by ARKesti
Static and Dynamic characteristics of Measurement System by ARKesti
Published: 2017/09/08
Channel: Archana Kesti
Auto length Measurement System
Auto length Measurement System
Published: 2011/11/30
Channel: Viney Ugave
What is Sexagesimal system of measurement?
What is Sexagesimal system of measurement?
Published: 2014/02/26
Channel: AppuSeriesAcademy
METRIC division (different units of measurement)
METRIC division (different units of measurement)
Published: 2013/05/23
Channel: apprenticemath
Math in Science: Comparing Metric Units of Measurement
Math in Science: Comparing Metric Units of Measurement
Published: 2015/01/20
Channel: RicochetScience
FingerTPS (Wiresless Tactile Measurement System) by Pressure Profile Systems
FingerTPS (Wiresless Tactile Measurement System) by Pressure Profile Systems
Published: 2008/09/29
Channel: PressureProfile
Lumo outdoor measurement system
Lumo outdoor measurement system
Published: 2017/05/09
Channel: StopPress
measurement the resistance of solid for grounding and earthing system
measurement the resistance of solid for grounding and earthing system
Published: 2017/01/05
Channel: shrief abou lailah
Quick Image 2D vision measurement system.
Quick Image 2D vision measurement system.
Published: 2015/03/09
Channel: MitutoyoEuropeGmbH
Timber measurement system
Timber measurement system
Published: 2012/04/16
Channel: Си Тех Си Тех
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WIKIPEDIA ARTICLE

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A system of measurement is a collection of units of measurement and rules relating them to each other. Systems of measurement have historically been important, regulated and defined for the purposes of science and commerce. Systems of measurement in modern use include the metric system, the imperial system, and United States customary units.

History[edit]

The French Revolution gave rise to the metric system, and this has spread around the world, replacing most customary units of measure. In most systems, length (distance), mass, and time are base quantities.

Later science developments showed that either electric charge or electric current could be added to extend the set of base quantities by which many other metrological units could be easily defined. (However, electrical units are not necessary for such a set. Gaussian units, for example, have only length, mass, and time as base quantities, and the ampere is defined in terms of other units.) Other quantities, such as power and speed, are derived from the base set: for example, speed is distance per unit time. Historically a wide range of units was used for the same type of quantity: in different contexts, length was measured in inches, feet, yards, fathoms, rods, chains, furlongs, miles, nautical miles, stadia, leagues, with conversion factors which were not powers of ten. Such arrangements were satisfactory in their own contexts.

The preference for a more universal and consistent system (based on more rational base units) only gradually spread with the growth of science. Changing a measurement system has substantial financial and cultural costs which must be offset against the advantages to be obtained from using a more rational system. However pressure built up, including from scientists and engineers for conversion to a more rational, and also internationally consistent, basis of measurement.

In antiquity, systems of measurement were defined locally: the different units might be defined independently according to the length of a king's thumb or the size of his foot, the length of stride, the length of arm, or maybe the weight of water in a keg of specific size, perhaps itself defined in hands and knuckles. The unifying characteristic is that there was some definition based on some standard. Eventually cubits and strides gave way to "customary units" to meet the needs of merchants and scientists.

In the metric system and other recent systems, a single basic unit is used for each base quantity. Often secondary units (multiples and submultiples) are derived from the basic units by multiplying by powers of ten, i.e. by simply moving the decimal point. Thus the basic metric unit of length is the metre; a distance of 1.234 m is 1,234 millimetres, or 0.001234 kilometres.

Current practice[edit]

Metrication is complete or nearly complete in almost all countries. US customary units are heavily used in the United States and to some degree in Liberia. Traditional Burmese units of measurement are used in Burma. U.S. units are used in limited contexts in Canada due to the large volume of trade; there is also considerable use of Imperial weights and measures, despite de jure Canadian conversion to metric.

A number of other jurisdictions have laws mandating or permitting other systems of measurement in some or all contexts, such as the United Kingdom – whose road signage legislation, for instance, only allows distance signs displaying imperial units (miles or yards)[1] – or Hong Kong.[2]

In the United States, metric units are used almost universally in science, widely in the military, and partially in industry, but customary units predominate in household use. At retail stores, the liter is a commonly used unit for volume, especially on bottles of beverages, and milligrams, rather than grains, are used for medications. Some other standard non-SI units are still in international use, such as nautical miles and knots in aviation and shipping.

Metric system[edit]

A baby bottle that measures in three measurement systems—metric, imperial (UK), and US customary.

Metric systems of units have evolved since the adoption of the first well-defined system in France in 1795. During this evolution the use of these systems has spread throughout the world, first to non-English-speaking countries, and then to English speaking countries.

Multiples and submultiples of metric units are related by powers of ten and their names are formed with prefixes. This relationship is compatible with the decimal system of numbers and it contributes greatly to the convenience of metric units.

In the early metric system there were two base units, the metre for length and the gram for mass. The other units of length and mass, and all units of area, volume, and derived units such as density were derived from these two base units.

Mesures usuelles (French for customary measurements) were a system of measurement introduced as a compromise between the metric system and traditional measurements. It was used in France from 1812 to 1839.

A number of variations on the metric system have been in use. These include gravitational systems, the centimetre–gram–second systems (cgs) useful in science, the metre–tonne–second system (mts) once used in the USSR and the metre–kilogram–second system (mks).

The current international standard metric system is the International System of Units (Système international d'unités or SI) It is an mks system based on the metre, kilogram and second as well as the kelvin, ampere, candela, and mole.

The SI includes two classes of units which are defined and agreed internationally. The first of these classes includes the seven SI base units for length, mass, time, temperature, electric current, luminous intensity and amount of substance. The second class consists of the SI derived units. These derived units are defined in terms of the seven base units. All other quantities (e.g. work, force, power) are expressed in terms of SI derived units.

Imperial and US customary units[edit]

Both imperial units and US customary units derive from earlier English units. Imperial units were mostly used in the former British Empire and the British Commonwealth, but in all these countries they have been largely supplanted by the metric system. They are still used for some applications in the United Kingdom but have been mostly replaced by the metric system in commercial, scientific, and industrial applications. US customary units, however, are still the main system of measurement in the United States. While some steps towards metrication have been made (mainly in the late 1960s and early 1970s), the customary units have a strong hold due to the vast industrial infrastructure and commercial development.

While imperial and US customary systems are closely related, there are a number of differences between them. Units of length and area (the inch, foot, yard, mile etc.) are identical except for surveying purposes.[clarification needed] The Avoirdupois units of mass and weight differ for units larger than a pound (lb). The imperial system uses a stone of 14 lb, a long hundredweight of 112 lb and a long ton of 2240 lb. The stone is not used in the US and the hundredweights and tons are short: 100 lb and 2000 lb respectively.

Where these systems most notably differ is in their units of volume. A US fluid ounce (fl oz), about 29.6 millilitres (ml), is slightly larger than the imperial fluid ounce (about 28.4 ml). However, as there are 16 US fl oz to a US pint and 20 imp fl oz per imperial pint, the imperial pint is about 20% larger. The same is true of quarts, gallons, etc. Six US gallons are a little less than five imperial gallons.

The Avoirdupois system served as the general system of mass and weight. In addition to this there are the Troy and the Apothecaries' systems. Troy weight was customarily used for precious metals, black powder and gemstones. The troy ounce is the only unit of the system in current use; it is used for precious metals. Although the troy ounce is larger than its Avoirdupois equivalent, the pound is smaller. The obsolete troy pound was divided into 12 ounces, rather than the 16 ounces per pound of the Avoirdupois system. The Apothecaries' system was traditionally used in pharmacology, but has now been replaced by the metric system; it shared the same pound and ounce as the troy system but with different further subdivisions.

Natural units[edit]

Natural units are physical units of measurement defined in terms of universal physical constants in such a manner that selected physical constants take on the numerical value of one when expressed in terms of those units. Natural units are so named because their definition relies on only properties of nature and not on any human construct. Various systems of natural units are possible.

Some other examples are as follows:

Non-standard units[edit]

Non-standard measurement units, sometimes found in books, newspapers etc., include:

Area[edit]

  • The American football field, which has a playing area 100 yards (91.4 m) long by 160 feet (48.8 m) wide. This is often used by the American public media for the sizes of large buildings or parks. It is used both as a unit of length (100 yd or 91.4 m, the length of the playing field excluding goal areas) and as a unit of area (57,600 sq ft or 5,350 m2), about 1.32 acres (0.53 ha).
  • British media also frequently uses the football pitch for equivalent purposes, although soccer pitches are not of a fixed size, but instead can vary within defined limits (100–130 yd or 91.4–118.9 m long, and 50–100 yd or 45.7–91.4 m wide, giving an area of 5,000 to 13,000 sq yd or 4,181 to 10,870 m2). However the UEFA Champions League field must be exactly 105 by 68 m (114.83 by 74.37 yd) giving an area of 7,140 m2 (0.714 ha) or 8,539 sq yd (1.764 acres). Example: HSS vessels are aluminium catamarans about the size of a football pitch... - Belfast Telegraph 23 June 2007
  • Larger areas are sometimes expressed as a multiple of the areas of certain American states, or subdivisions of the UK etc.

Energy[edit]

Units of currency[edit]

A unit of measurement that applies to money is called a unit of account in economics and unit of measure in accounting.[3] This is normally a currency issued by a country or a fraction thereof; for instance, the US dollar and US cent (1100 of a dollar), or the euro and euro cent.

ISO 4217 is the international standard describing three letter codes (also known as the currency code) to define the names of currencies established by the International Organization for Standardization (ISO).

Historical systems of measurement[edit]

Throughout history, many official systems of measurement have been used. While no longer in official use, some of these customary systems are occasionally used in day-to-day life, for instance in cooking.

Africa[edit]

Asia[edit]

Europe[edit]

North America[edit]

Oceania[edit]

South America[edit]

See also[edit]

Conversion tables[edit]

Notes and references[edit]

  1. ^ "Statutory Instrument 2002 No. 3113 The Traffic Signs Regulations and General Directions 2002". Her Majesty's Stationery Office (HMSO). 2002. Retrieved 18 March 2010. 
  2. ^ HK Weights and Measures Ordinance
  3. ^ Financial Accounting Standards Research Initiative: The Unit of Account Issue
  4. ^ M. Ismail Marcinkowski, Measures and Weights in the Islamic World. An English Translation of Professor Walther Hinz's Handbook "Islamische Maße und Gewichte", with a foreword by Professor Bosworth, F.B.A. Kuala Lumpur, ISTAC, 2002, ISBN 983-9379-27-5. This work is an annotated translation of a work in German by the late German orientalist Walther Hinz, published in the Handbuch der Orientalistik, erste Abteilung, Ergänzungsband I, Heft 1, Leiden, The Netherlands: E. J. Brill, 1970.

Bibliography[edit]

External links[edit]

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