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Pound (mass)

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118-457: The pound or pound-mass is a unit of mass used in both the British imperial and United States customary systems of measurement . Various definitions have been used; the most common today is the international avoirdupois pound, which is legally defined as exactly 0.453 592 37   kilograms , and which is divided into 16 avoirdupois ounces . The international standard symbol for

236-410: A kentēnarion ( κεντηνάριον , "hundredweight"). Its weight seems to have decreased gradually from the original 324 g (11.4 oz) to 319 g (11.3 oz). Due to its association with gold, it was also known as the chrysaphikē litra ( χρυσαφική λίτρα , "gold pound") or thalassia litra ( θαλάσσια λίτρα , "maritime pound"), but it could also be used as a measure of land, equalling

354-483: A barleycorn . A system of measurement is a collection of units of measurement and rules relating them to each other. As science progressed, a need arose to relate the measurement systems of different quantities, like length and weight and volume. The effort of attempting to relate different traditional systems between each other exposed many inconsistencies, and brought about the development of new units and systems. Systems of units vary from country to country. Some of

472-526: A White House advisor to the Reagan administration, to reduce federal spending—the USMB was disbanded in the autumn of 1982. The ending of the USMB increased doubts that metrication would really be implemented. Public and private sector metrication slowed even while competitiveness between nations and demands of global marketplaces increased. The American National Metric Council (ANMC) was established in 1973 by

590-489: A crucial role in human endeavour from early ages up to the present. A multitude of systems of units used to be very common. Now there is a global standard, the International System of Units (SI), the modern form of the metric system . In trade, weights and measures are often a subject of governmental regulation, to ensure fairness and transparency. The International Bureau of Weights and Measures (BIPM)

708-572: A fortieth of the thalassios modios . The soualia litra was specifically used for weighing olive oil or wood, and corresponded to 4/5 of the logarikē or 256 g (9.0 oz). Some outlying regions, especially in later times, adopted various local measures, based on Italian, Arab or Turkish measures. The most important of these was the argyrikē litra ( αργυρική λίτρα , "silver pound") of 333 g (11.7 oz), found in Trebizond and Cyprus , and probably of Arab origin. Since

826-480: A groove about 0.34 inches (8.6 mm) from the top, to allow the cylinder to be lifted using an ivory fork. It was constructed following the destruction of the Houses of Parliament by fire in 1834, and is stamped "P.S. 1844, 1 lb" (P.S. stands for "Parliamentary Standard"). The British Weights and Measures Act 1878 ( 41 & 42 Vict. c. 49) said that contracts worded in terms of metric units would be deemed by

944-525: A measurement of length or mass shall be made in the United Kingdom; and- (a) the yard shall be 0.9144 metre exactly; (b) the pound shall be 0.453 592 37 kilogram exactly. An avoirdupois pound is equal to 16 avoirdupois ounces and to exactly 7,000 grains . The conversion factor between the kilogram and the international pound was therefore chosen to be divisible by 7 with a terminating decimal representation, and an (international) grain

1062-717: A petition was created on the White House's petitioning system , petitioning the White House to "Make the Metric system the standard in the United States, instead of the Imperial system." On January 10, 2013, this petition garnered over 25,000 signatures, exceeding the, at the time, threshold needed to require the Obama Administration to officially respond to the petition. Patrick D. Gallagher , director of

1180-424: A quantity may be described as multiples of that of a familiar entity, which can be easier to contextualize than a value in a formal unit system. For instance, a publication may describe an area in a foreign country as a number of multiples of the area of a region local to the readership. The propensity for certain concepts to be used frequently can give rise to loosely defined "systems" of units. For most quantities

1298-500: A result, units of measure could vary not only from location to location but from person to person. Units not based on the human body could be based on agriculture, as is the case with the furlong and the acre , both based on the amount of land able to be worked by a team of oxen . Metric systems of units have evolved since the adoption of the original metric system in France in 1791. The current international standard metric system

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1416-519: A series of measurements known as pounds ( Latin : libra , Ancient Greek : λίτρα , romanized :  litra ). The most common was the logarikē litra ( λογαρική λίτρα , "pound of account"), established by Constantine the Great in 309/310. It formed the basis of the Byzantine monetary system , with one litra of gold equivalent to 72 solidi . A hundred litrai were known as

1534-706: A series of well-attended annual conferences. Subsequently, a series of National Metric Conferences, jointly sponsored by the ANMC, the U.S. Metric Association (USMA), the Department of Commerce, and the National Institute of Standards and Technology (NIST), were held from 1989 through 1993. Congress included new encouragement for U.S. industrial metrication in the Omnibus Foreign Trade and Competitiveness Act of 1988. This legislation amended

1652-570: A set of standard metric weights and measures. In 1875, the United States solidified its commitment to the development of the internationally recognized metric system by becoming one of the original seventeen signatory nations to the Metre Convention , also known as the Treaty of the Metre. The signing of this international agreement concluded five years of meetings in which the metric system

1770-400: A small set of units is required. These units are taken as the base units and the other units are derived units . Thus base units are the units of the quantities which are independent of other quantities and they are the units of length, mass, time, electric current, temperature, luminous intensity and the amount of substance. Derived units are the units of the quantities which are derived from

1888-520: A troy pound, is still used for measurements of gems such as opals, and precious metals such as silver, platinum and particularly gold. A tower pound is equal to 12 tower ounces and to 5,400 troy grains , which equals around 350 grams. The tower pound is the historical weight standard that was used for England's coinage. Before the Norman conquest in 1066, the tower pound was known as the Saxon pound. During

2006-544: A uniform system. The United States was one of the first nations to adopt a decimal currency , under the Coinage Act of 1792 . In 1793, Thomas Jefferson requested artifacts from France that could be used to adopt the metric system in the United States, and Joseph Dombey was sent from France with a standard kilogram. Before reaching the United States, Dombey's ship was blown off course by a storm and captured by pirates, and he died in captivity on Montserrat . In 1832,

2124-476: A unit conversion. In some agricultural areas, pecks or bushels can denote quantities of apples etc. by dry volume. Since 1992, the federal Fair Packaging and Labeling Act (FPLA) has required most packaged consumer goods to be labeled in both customary and metric units. Some industries are engaged in efforts to amend this law to allow manufacturers to use only metric labeling. Forty-eight U.S. states have adopted laws permitting labeling in only metric units,

2242-433: A unit is necessary to communicate values of that physical quantity. For example, conveying to someone a particular length without using some sort of unit is impossible, because a length cannot be described without a reference used to make sense of the value given. But not all quantities require a unit of their own. Using physical laws, units of quantities can be expressed as combinations of units of other quantities. Thus only

2360-644: A unit of mass effective 1 January 1840 by a decree of 4 July 1837, but is still used informally. Originally derived from the Roman libra, the definition varied throughout the Holy Roman Empire in the Middle Ages and onward. For example, the measures and weights of the Habsburg monarchy were reformed in 1761 by Empress Maria Theresa of Austria. The unusually heavy Habsburg (civil) pound of 16 ounces

2478-421: Is 22 mm wide by 80 mm long). Consumer-size photographic film is commonly sold in a 35 mm standard (24×36 mm negative), although print sizes and large format films are defined in inches. Digital camera sensor sizes are measured in an archaic manner indicating inverse fractions of an inch representing the diameter of an equivalent vidicon tube. For example, a 1 ⁄ 1.6 in sensor

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2596-495: Is available in 35-, 40-, and 50-meter packages). Perhaps the most common metric item sold is the two-liter bottle . Some supermarket chains also make their store brand soft drinks available in 3-liter sizes. Soft drink containers of 1 and 0.5 liters (and more recently 1.25 liter bottles) are increasingly sold alongside 12 fl oz , 16 fl oz, 20 fl oz, and 24 fl oz (355, 473, 591 and 710 mL) sizes. The half-liter water bottle (16.9 fl oz) has nearly replaced

2714-485: Is central to the scientific method . A standard system of units facilitates this. Scientific systems of units are a refinement of the concept of weights and measures historically developed for commercial purposes. Science , medicine , and engineering often use larger and smaller units of measurement than those used in everyday life. The judicious selection of the units of measurement can aid researchers in problem solving (see, for example, dimensional analysis ). In

2832-488: Is currently required. The goal of these changes would be to encourage metric labeling, leading to greater agreement of U.S. labeling laws and simplifying domestic and international commerce. NIST Metric Program coordinator Elizabeth Gentry added that the proposed changes were "in response to requests by U.S. manufacturers and consumers", particularly that "manufacturers want to take control of the limited net quantity of contents real estate on their packaging." In December 2012,

2950-409: Is expressed as the product of a numerical value { Z } (a pure number) and a unit [ Z ]: For example, let Z {\displaystyle Z} be "2 metres"; then, { Z } = 2 {\displaystyle \{Z\}=2} is the numerical value and [ Z ] = m e t r e {\displaystyle [Z]=\mathrm {metre} } is the unit. Conversely,

3068-583: Is government policy and metric (SI) program to implement and assist with metrication, however there is major social resistance for further metrication. Although customary units are used more often than metric units in the U.S., the SI system is used extensively in fields such as science, medicine, electronics, the military, automobile production and repair, and international affairs. Post-1994 federal law also mandates most packaged consumer goods be labeled in both customary and metric units. The U.S. has fully adopted

3186-467: Is now defined as exactly 0.0254  m , and the US and imperial avoirdupois pound is now defined as exactly 0.453 592 37   kg . While the above systems of units are based on arbitrary unit values, formalised as standards, natural units in physics are based on physical principle or are selected to make physical equations easier to work with. For example, atomic units (au) were designed to simplify

3304-514: Is specified in lumens , derived from the candela rather than the candle . The letter K is commonly used to denote "thousand" (e.g., "She earns $ 80K"), even though this is inconsistent with the lowercase "k" in SI. This usage has largely replaced the letter "G" (for " grand ", used almost exclusively for money) and the Roman numeral M that was commonly used for "thousand" before the 1960s. The "M" has now come to denote "million" (e.g., "$ 32.5M budget"). Calculations show annual savings due to

3422-478: Is tasked with ensuring worldwide uniformity of measurements and their traceability to the International System of Units (SI). Metrology is the science of developing nationally and internationally accepted units of measurement. In physics and metrology, units are standards for measurement of physical quantities that need clear definitions to be useful. Reproducibility of experimental results

3540-489: Is the International System of Units (abbreviated to SI). An important feature of modern systems is standardization . Each unit has a universally recognized size. Both the imperial units and US customary units derive from earlier English units . Imperial units were mostly used in the British Commonwealth and the former British Empire . US customary units are still the main system of measurement used in

3658-514: Is the conversion of the unit of measurement in which a quantity is expressed, typically through a multiplicative conversion factor that changes the unit without changing the quantity. This is also often loosely taken to include replacement of a quantity with a corresponding quantity that describes the same physical property. One example of the importance of agreed units is the failure of the NASA Mars Climate Orbiter , which

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3776-578: Is the origin of the abbreviation for pound, "lb". A number of different definitions of the pound have historically been used in Britain. Among these are the avoirdupois pound , which is the common pound used for weights, and the obsolete tower , merchants' and London pounds. The troy pound and ounce remain in use only for the weight of precious metals , especially in their trade. The weights of traded precious metals, such as gold and silver, are normally quoted just in ounces (e.g. "500 ounces") and, when

3894-480: Is thus equal to exactly 64.798 91   milligrams . In the United Kingdom, the process of metrication and European units of measurement directives were expected to eliminate the use of the pound and ounce, but in 2007 the European Commission abandoned the requirement for metric-only labelling on packaged goods there, and allowed for dual metric – imperial marking to continue indefinitely. In

4012-884: The 4th and 3rd millennia BC among the ancient peoples of Mesopotamia , Egypt and the Indus Valley , and perhaps also Elam in Persia as well. Weights and measures are mentioned in the Bible (Leviticus 19:35–36). It is a commandment to be honest and have fair measures. In the Magna Carta of 1215 (The Great Charter) with the seal of King John , put before him by the Barons of England, King John agreed in Clause 35 "There shall be one measure of wine throughout our whole realm, and one measure of ale and one measure of corn—namely,

4130-611: The American National Standards Institute (ANSI) as a non-profit, tax-exempt organization for planning and coordinating metric activity in all sectors of the U.S. economy. The ANMC became a separately incorporated organization in 1976. The ANMC was intended to facilitate U.S. metrication by maintaining a voluntary and orderly process that minimizes costs and maximizes benefits, and to provide information, forums, individual assistance, and other services for its subscribers. The ANMC attempted to coordinate

4248-481: The French livre poids de marc . The trone pound is one of a number of obsolete Scottish units of measurement . It was equivalent to between 21 and 28 avoirdupois ounces (about 600–800 g (21–28 oz)). Units of measurement A unit of measurement , or unit of measure , is a definite magnitude of a quantity , defined and adopted by convention or by law, that is used as a standard for measurement of

4366-477: The Martian atmosphere . The effort toward national metrication is based on the premise that the U.S. industrial and commercial productivity, mathematics, and science education, and the competitiveness of its products and services in world markets would be enhanced by adopting the metric system. Gerard Iannelli, director of the U.S. Metric Program, gave the opinion that Americans have so far not done so because of

4484-600: The Secretary of Commerce "to charter an Interagency Council on Metric Policy ("ICMP"), which will assist the Secretary in coordinating Federal Government-wide implementation of this order." Some members of Congress attempted to ban use of the metric system on federal highways in 1992 and 1993. These bills were not popular in the House of Representatives and failed before a vote. The use of two different unit systems caused

4602-456: The Tower of London . The tower system ran concurrently with the avoirdupois and troy systems until the reign of Henry VIII , when a royal proclamation dated 1526 required that the troy pound be used for mint purposes instead of the tower pound. No standards of the tower pound are known to have survived. The tower pound was also called the moneyers' pound (referring to the Saxon moneyers before

4720-484: The United States outside of science, medicine, many sectors of industry, and some of government and military, and despite Congress having legally authorised metric measure on 28 July 1866. Some steps towards US metrication have been made, particularly the redefinition of basic US and imperial units to derive exactly from SI units. Since the international yard and pound agreement of 1959 the US and imperial inch

4838-565: The apothecaries' system of weights. Troy weight may take its name from the French market town of Troyes in France where English merchants traded at least as early as the early 9th century. The troy pound is no longer in general use or a legal unit for trade (it was abolished in the United Kingdom on 6 January 1879 by the Weights and Measures Act 1878 ), but the troy ounce, 1 ⁄ 12 of

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4956-528: The departements : Roer , Sarre , Rhin-et-Moselle , and Mont-Tonnerre . As a result of the Congress of Vienna , these regions again became part of various German states. However, many of these regions retained the metric system and adopted a metric pound of precisely 500 g (17.64 oz). In 1854, the pound of 500 g also became the official mass standard of the German Customs Union and

5074-401: The metric system , the imperial system , and United States customary units . Historically many of the systems of measurement which had been in use were to some extent based on the dimensions of the human body. Such units, which may be called anthropic units , include the cubit , based on the length of the forearm; the pace , based on the length of a stride; and the foot and hand . As

5192-553: The social sciences , there are no standard units of measurement. A unit of measurement is a standardized quantity of a physical property, used as a factor to express occurring quantities of that property. Units of measurement were among the earliest tools invented by humans. Primitive societies needed rudimentary measures for many tasks: constructing dwellings of an appropriate size and shape, fashioning clothing, or bartering food or raw materials. The earliest known uniform systems of measurement seem to have all been created sometime in

5310-652: The 14th century for goods other than money and medicine (" electuaries "). The London pound is that of the Hansa , as used in their various trading places. The London pound is based on 16 ounces, each ounce divided as the tower ounce. It never became a legal standard in England; the use of this pound waxed and waned with the influence of the Hansa itself. A London pound was equal to 7,200 troy grains (16 troy ounces) or, equivalently, 10,240 tower grains (16 tower ounces). In

5428-454: The 16 ounce size. 700 mL (23.6 fl oz) and one-liter sizes are also common, though 20 fl oz and 24 fl oz sizes remain popular, particularly in vending machines. Attempts to sell 3- or 4-liter jugs of milk , instead of gallons (3.785 L), have been largely unsuccessful, and such bottles are rarely seen in the United States. Milk remains sold in binary divisions of the gallon, with half-pints, pints , quarts and half-gallons being

5546-412: The 19th century, and the SI has been the "preferred system of weights and measures for United States trade and commerce" since 1975 according to United States law. However, conversion was not mandatory and many industries chose not to convert, and U.S. customary units remain in common use in many industries as well as in governmental use (for example, speed limits are still posted in miles per hour). There

5664-463: The Cologne standard. This arrátel was introduced in 1499 by Manuel I , king of Portugal . Based on an evaluation of bronze nesting weight piles distributed by Manuel I to different towns, the arrátel of Manuel I has been estimated to be of 457.8 g (16.15 oz). In the early 19th century, the arrátel was evaluated at 459 g (16.2 oz). In the 15th century, the arrátel

5782-626: The London quart;—and one width of dyed and russet and hauberk cloths—namely, two ells below the selvage..." As of the 21st century, the International System is predominantly used in the world. There exist other unit systems which are used in many places such as the United States Customary System and the Imperial System. The United States is the only industrialized country that has not yet at least mostly converted to

5900-610: The Metric Conversion Act of 1975 and designated the metric system as "the Preferred system of weights and measures for United States trade and commerce". The legislation states that the federal government has a responsibility to assist industry, especially small business, as it voluntarily converts to the metric system of measurement. The legislation required most federal agencies to use the metric system in their procurement, grants, and other business-related activities by

6018-411: The Middle Ages, various pounds ( livre ) have been used in France. Since the 19th century, a livre has referred to the metric pound , 500 g. The livre esterlin is equivalent to about 367.1 grams (5,665 gr) and was used between the late 9th century and the mid-14th century. The livre poids de marc or livre de Paris is equivalent to about 489.5 grams (7,554 gr) and

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6136-570: The National Institute of Standards and Technology, provided the official response stating that customary units were defined in the metric system, thus making the nation "bilingual" in terms of measurement systems. Gallagher also said that using the metric system was a choice to be made by individuals. Early in 2013, state Representative Karl Rhoads introduced bill HB36 into the Hawaii House of Representatives that sought to make

6254-820: The Norman conquest); the easterling pound , which may refer to traders of eastern Germany, or to traders on the shore of the eastern Baltic sea , or dealers of Asiatic goods who settled at the London Steelyard wharf ; and the Rochelle pound by French writers, because it was also in use at La Rochelle . An almost identical weight was employed by the Germans for weighing gold and silver. The mercantile pound (1304) of 6750 troy grains, or 9600 Tower grains, derives from this pound, as 25 shilling -weights or 15 Tower ounces, for general commercial use. Multiple pounds based on

6372-403: The Roman libra pondo ('the weight measured in libra '), and is cognate with, among others, German Pfund , Dutch pond , and Swedish pund . These units are now designated as historical and are no longer in common usage, being replaced by the metric system . Usage of the unqualified term pound reflects the historical conflation of mass and weight . This accounts for

6490-417: The SI means that the pound is now defined precisely in terms of fundamental constants, ending the era of its definition in terms of physical prototypes. A troy pound (abbreviated lb t) is equal to 12 troy ounces and to 5,760 grains, that is exactly 373.241 7216 grams. Troy weights were used in England by jewellers. Apothecaries also used the troy pound and ounce, but added the drachms and scruples unit in

6608-471: The SI unit for time, the second . The U.S. has a national policy to adopt the metric system. All U.S. agencies are required to adopt the metric system. Immediately after gaining independence from Great Britain , the United States used a variety of units of measure, including Dutch units and English units . The 1789 Constitution grants Congress the authority to determine standards of measure, though it did not immediately use this authority to impose

6726-603: The State." This section was repealed, effective July 1, 1987. On July 4, 1876, Melvil Dewey (known for his Dewey Decimal Classification ) incorporated the American Metric Bureau in Boston to sell rulers and other metric measuring tools. Dewey had hoped to make his fortune selling metric supplies. The General Conference on Weights and Measures is the governing body for the modern metric system and comprises

6844-472: The United States, the Metric Conversion Act of 1975 declared the metric system to be the "preferred system of weights and measures" but did not suspend use of United States customary units , and the United States is the only industrialised country where commercial activities do not predominantly use the metric system, despite many efforts to do so , and the pound remains widely used as one of

6962-631: The United States, the avoirdupois pound as a unit of mass has been officially defined in terms of the kilogram since the Mendenhall Order of 1893 . That order defined the pound to be 2.204 62 pounds to a kilogram. The following year, this relationship was refined as 2.204 622 34 pounds to a kilogram, following a determination of the British pound. In 1959, the United States National Bureau of Standards redefined

7080-475: The avoirdupois pound existed, and when measured in troy grains they were found to be of 7,002 grains and 6,999 grains. In the United Kingdom, weights and measures have been defined by a long series of Acts of Parliament, the intention of which has been to regulate the sale of commodities. Materials traded in the marketplace are quantified according to accepted units and standards in order to avoid fraud. The standards themselves are legally defined so as to facilitate

7198-474: The avoirdupois pound is lb ; an alternative symbol (when there might otherwise be a risk of confusion with the pound-force ) is lb m (for most pound definitions), # ( chiefly in the U.S. ), and ℔ or ″̶ (specifically for the apothecaries' pound ). The unit is descended from the Roman libra (hence the symbol lb , descended from the scribal abbreviation , ℔ ). The English word pound comes from

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7316-414: The base quantities and some of the derived units are the units of speed, work, acceleration, energy, pressure etc. Different systems of units are based on different choices of a set of related units including fundamental and derived units. Following ISO 80000-1 , any value or magnitude of a physical quantity is expressed as a comparison to a unit of that quantity. The value of a physical quantity Z

7434-473: The benefit of the cross-border Canadian audiences. Web-based and mobile weather forecasts typically can be switched to metric units. Some U.S. consumer products come in round metric sizes. This appears to be increasing because of the international nature of manufacturing, distribution, and sales. Many items are produced in round metric quantities and some manufacturers opt to display the metric quantity first or more prominently (e.g., Oral-B Glide dental floss

7552-403: The common metric units at school. Moreover, newer units introduced by engineers and scientists from the 18th century onwards, such as volts , megapixels , and kilotons and megatons of TNT , are generally formulated in terms of powers of 10. Use of units based on the SI is widespread for many applications. Residential electric power plans use kilowatt hours . The luminous flux from lamps

7670-522: The courts to be made according to the Imperial units defined in the Act, and a table of metric equivalents was supplied so that the Imperial equivalents could be legally calculated. This defined, in UK law, metric units in terms of Imperial ones. The equivalence for the pound was given as 1 lb = 453.592 65  g or 0.45359 kg, which made the kilogram equivalent to about 2.204 6213  lb . In 1883, it

7788-506: The crew confusing tower instructions (in metres) and altimeter readings (in feet). Three crew and five people on the ground were killed. Thirty-seven were injured. In 1983, a Boeing 767 (which thanks to its pilot's gliding skills landed safely and became known as the Gimli Glider ) ran out of fuel in mid-flight because of two mistakes in figuring the fuel supply of Air Canada 's first aircraft to use metric measurements. This accident

7906-574: The customary system of units was formalized. In the early 19th century, the U.S. Coast and Geodetic Survey , the government's surveying and map-making agency, used a meter standard ("Committee Meter", French: Mètre des Archives ) brought from Switzerland . Shortly after the American Civil War , the 39th United States Congress protected the use of the metric system in commerce with the Metric Act of 1866 and supplied each state with

8024-686: The definition of the pound given there remained in force until the 1960s. The pound was defined thus (Section 4) "The ... platinum weight ... deposited in the Standards department of the Board of Trade ... shall continue to be the imperial standard of ... weight ... and the said platinum weight shall continue to be the Imperial Standard for determining the Imperial Standard Pound for the United Kingdom". Paragraph 13 states that

8142-468: The different systems include the centimetre–gram–second , foot–pound–second , metre–kilogram–second systems, and the International System of Units , SI. Among the different systems of units used in the world, the most widely used and internationally accepted one is SI. The base SI units are the second, metre, kilogram, ampere, kelvin, mole and candela; all other SI units are derived from these base units. Systems of measurement in modern use include

8260-401: The drive bays differ from their name (e.g., 3 1 ⁄ 2 " drive bays are actually 4 inches (101.6 mm) wide, because 3 1 ⁄ 2 " refers to the historical platter diameter inside the drive). The newer 2 1 ⁄ 2 inch and 1.8 inch drive bays are specified in metric and use metric mounting screws. Newer SSDs in the M.2 form factor are measured in millimeters (e.g., "M.2 2280"

8378-526: The effort it takes to "translate" from customary to metric units when both measurements are not shown. He also cited what he perceived to be ineffective attempts at public education and awareness. In June 2010, NIST called for an amendment to the Fair Packaging and Labeling Act that would allow manufacturers the option to voluntarily label their packages solely in metric units, rather than being dual-labeled with U.S. customary units and metric units as

8496-632: The elimination of English measures from instruction ranging from $ 1.603 billion to $ 2.506 billion per year. Over time, the total savings would accumulate to a present discounted value of between $ 53.4 to $ 83.5 billion. Televised and radio weather reports are given in degrees Fahrenheit instead of Celsius for dew point and air temperatures, miles per hour for wind speed, inches of mercury for atmospheric pressure ( millibars are used only when reporting tropical phenomena such as hurricanes), and other customary units. In some northern border states , temperatures are described in both Fahrenheit and Celsius for

8614-448: The end of 1992. While not mandating metric use in the private sector, the federal government has sought to serve as a catalyst in the metric conversion of the country's trade, industry, and commerce. Exceptions were made for the highway and construction industries. The Department of Transportation planned to require metric units by 2000, but this plan was canceled by the 1998 highway bill TEA21 . The U.S. military has generally high use of

8732-400: The existing legal definition of the UK pound differed from the international standard pound by 0.06 milligrams . To remedy this, the pound was again redefined in the United Kingdom by the Weights and Measures Act 1963 to match the international pound, stating: "the pound shall be 0.453 592 37 kilogramme exactly", a definition which remains valid to the present day. The 2019 revision of

8850-457: The fundamental standards for length and mass in the United States, though some metric standards were used in practice before then. The definitions of United States customary units , such as the foot and pound, have been based on metric units since then. The 1895 Constitution of Utah , in Article X, Section 11, originally mandated that: "The Metric System shall be taught in the public schools of

8968-515: The increasing influence of technology in the United States. The U.S. Metric Study recommended that the United States implement a carefully planned transition to the principal use of the metric system over a decade. Congress passed the Metric Conversion Act of 1975 "to coordinate and plan the increasing use of the metric system in the United States". Voluntary conversion was initiated, and the United States Metric Board (USMB)

9086-464: The key customary units. Historically, in different parts of the world, at different points in time, and for different applications, the pound (or its translation) has referred to broadly similar but not identical standards of mass or force. The libra (Latin for 'scale'/'balance') is an ancient Roman unit of mass that is now equivalent to 328.9 g (11.60 oz). It was divided into 12 unciae (singular: uncia ), or ounces. The libra

9204-626: The loss of the Mars Climate Orbiter on September 23, 1999. NASA specified metric units in the contract. NASA and other organizations applied metric units in their work, but one subcontractor, Lockheed Martin , provided software that calculated and reported thruster performance data to the team in pound-force-seconds, rather than the expected newton-seconds. The spacecraft was intended to orbit Mars at about 150 kilometers (93 mi) altitude, but incorrect data caused it to descend instead to about 57 kilometers (35 mi), burning up in

9322-399: The metric planning of many industrial sectors, unlike the USMB, which only attempted to implement the policy set forth in the Metric Conversion Act of 1975. After the formation of the USMB, committees of the ANMC submitted conversion plans for the chemical sector and for the instruments sector. These sector conversion plans were later approved by the USMB. From 1975 through 1987, the ANMC held

9440-600: The metric system mandatory within his state. Called "Relating to the Metric System", the bill stipulated that the law would come into effect on January 1, 2018. By June 2014, bill HB36 had not gained enough support and was considered dead. However, in January 2019, Rhoads presented bill SB428 to the Hawaii State Legislature , saying that "strong reasons exist for Hawaii and other states to switch to

9558-421: The metric system". It was proposed to establish a task force to explore the use of the metric system for distance and speed measurements on public signs. If either bill had become law, Hawaii would have been the first state to introduce the metric system on a broad scale. In January 2015, Oregon State Senator Brian Boquist , at the request of metric enthusiast David Pearl, proposed Oregon Senate Bill 166, which

9676-503: The metric system, except where this would have an obvious detrimental effect. In 1968, Congress authorized the U.S. Metric Study , a three-year study of systems of measurement in the United States, with emphasis on the feasibility of metrication. The United States Department of Commerce conducted the study. A 45-member advisory panel consulted and took testimony from hundreds of consumers, business organizations, labor groups, manufacturers, and state and local officials. The final report of

9794-565: The metric system, partly because of the need to work with other nations' militaries. Executive Order 12770 , signed by President George H. W. Bush on July 25, 1991, citing the Metric Conversion Act, directed departments and agencies within the executive branch of the United States Government to "take all appropriate measures within their authority" to use the metric system "as the preferred system of weights and measures for United States trade and commerce", and authorized

9912-410: The metric system. In Norway, the same name was used for a weight of 425.076 g (14.9941 oz). In Denmark, it equaled 471 g (16.6 oz). In the 19th century, Denmark followed Germany's lead and redefined the pound as 500 g (18 oz). The Portuguese unit that corresponds to the pounds of different nations is the arrátel , equivalent to 16 ounces of Colonha , a variant of

10030-576: The metric system. The systematic effort to develop a universally acceptable system of units dates back to 1790 when the French National Assembly charged the French Academy of Sciences to come up such a unit system. This system was the precursor to the metric system which was quickly developed in France but did not take on universal acceptance until 1875 when The Metric Convention Treaty was signed by 17 nations. After this treaty

10148-539: The modern distinguishing terms pound-mass and pound-force . The word 'pound' and its cognates ultimately derive from a borrowing into Proto-Germanic of the Latin expression libra pondo ('the weight measured in libra '), in which the word pondo is the ablative singular of the Latin noun pondus ('weight'). The United States and the Commonwealth of Nations agreed upon common definitions for

10266-524: The nominal design diameter of the replacement "3 1 ⁄ 2 inch" disks was actually 90 mm. CDs and DVDs are 120 mm in diameter, but their size is rarely mentioned; mini CDs are sometimes called 80 mm CDs. Computer fan sizes are exclusively referred to by metric units (120 mm or 80 mm case fans, for example), while hard disk drive and CD drive bay sizes are customary measurements, typically 3 1 ⁄ 2 inches and 5 1 ⁄ 4 inches, respectively. The actual size of

10384-425: The numerical value expressed in an arbitrary unit can be obtained as: Units can only be added or subtracted if they are the same type; however units can always be multiplied or divided, as George Gamow used to explain. Let Z {\displaystyle Z} be "2 metres" and W {\displaystyle W} "3 seconds", then There are certain rules that apply to units: Conversion of units

10502-499: The pound (avoirdupois) to be exactly equal to 0.453 592 37 kilograms, as had been declared by the International Yard and Pound Agreement of that year. According to a 1959 NIST publication, the United States 1894 pound differed from the international pound by approximately one part in 10 million. The difference is so insignificant that it can be ignored for almost all practical purposes. The Byzantines used

10620-456: The pound and the yard . Since 1 July 1959, the international avoirdupois pound (symbol lb) has been defined as exactly 0.453 592 37  kg . In the United Kingdom, the use of the international pound was implemented in the Weights and Measures Act 1963 . The yard or the metre shall be the unit of measurement of length and the pound or the kilogram shall be the unit of measurement of mass by reference to which any measurement involving

10738-402: The primary sizes. Shampoo , mouthwash , and dental floss have begun to be sold in metric sizes. PowerBars and similar products have always been sold (but not marketed) by the gram. Nutritional food labels typically report serving sizes in both systems but only list metric values (g or mg) for the breakdown of individual nutrients. Wine is sold in standard bottles of 750 mL, as in

10856-414: The reign of King Offa (757–96) of Mercia , a Saxon pound of silver was used to set the original weight of a pound sterling . From one Saxon pound of silver (that is a tower pound) the king had 240 silver pennies minted. In the pound sterling monetary system, twelve pennies equaled a shilling and twenty shillings equaled a pound sterling. The tower pound was referenced to a standard prototype found in

10974-442: The resolution of disputes brought to the courts; only legally defined measures will be recognised by the courts. Quantifying devices used by traders (weights, weighing machines, containers of volumes, measures of length) are subject to official inspection, and penalties apply if they are fraudulent. The Weights and Measures Act 1878 ( 41 & 42 Vict. c. 49) marked a major overhaul of the British system of weights and measures, and

11092-696: The rest of the world. A fifth of liquor, once one-fifth of a U.S. gallon, or 757 mL, is now commonly 750 mL, though it is still referred to as "a fifth". Beer is sold in fluid ounce denominations. Regulations are set by the Alcohol and Tobacco Tax and Trade Bureau which controls the permissible sizes of containers. Unlike non-alcoholic beverages, most alcohol products are not required to carry unit conversions on labels. Loose fruits and vegetables are near universally priced either per pound or per item. In both supermarkets and steakhouses, cuts of meat are sold in ounces and pounds. Loosely sold goods need not carry

11210-497: The same kind of quantity . Any other quantity of that kind can be expressed as a multiple of the unit of measurement. For example, a length is a physical quantity . The metre (symbol m) is a unit of length that represents a definite predetermined length. For instance, when referencing "10 metres" (or 10 m), what is actually meant is 10 times the definite predetermined length called "metre". The definition, agreement, and practical use of units of measurement have played

11328-408: The same ounce were quite common. In much of Europe, the apothecaries' and commercial pounds were different numbers of the same ounce. The merchants' pound ( mercantile pound , libra mercantoria , or commercial pound ) was considered to be composed of 25 rather than 20 Tower shillings of 12 pence . It was equal to 9,600 wheat grains (15 tower ounces or 6,750 grains) and was used in England until

11446-434: The same unit for the distance between two cities and the length of a needle. Thus, historically they would develop independently. One way to make large numbers or small fractions easier to read, is to use unit prefixes . At some point in time though, the need to relate the two units might arise, and consequently the need to choose one unit as defining the other or vice versa. For example, an inch could be defined in terms of

11564-478: The signing nations of the Treaty of the Metre. The General Conference on Weights and Measures approved an updated version of the metric system in 1960 named Le Système international d'unités ( International System of Units ) and abbreviated SI . On February 10, 1964, the National Bureau of Standards (now known as the National Institute of Standards and Technology ) issued a statement that it would use

11682-434: The size in centimeters. The original 1 ⁄ 4 inch (6.35 mm) phone connector jack dates back to 1878 and still sees use in audio equipment and electric instruments. In many respects, it has been superseded by the 3.5 mm connectors or 2.5 mm headset, which was common on older mobile phones. While early floppy disks had a nominal package size of 5 1 ⁄ 4 inches (approximately 130 mm),

11800-600: The size of the degree and for the circumference of the Earth was therefore about 25% too small. Historical Legal Metric information Metrication in the United States Metrication (or metrification) is the process of introducing the International System of Units , also known as SI units or the metric system , to replace a jurisdiction's traditional measuring units. U.S. customary units have been defined in terms of metric units since

11918-423: The study concluded that the U.S. would eventually join the rest of the world in the use of the metric system of measurement. The study found that metric units were already implemented in many areas and that their use was increasing. The majority of study participants believed that conversion to the metric system was in the best interests of the United States, particularly in view of the importance of foreign trade and

12036-461: The tower pound to the troy pound . The avoirdupois pound, also known as the wool pound, first came into general use c. 1300. It was initially equal to 6,992 troy grains. The pound avoirdupois was divided into 16 ounces. During the reign of Queen Elizabeth I , the avoirdupois pound was redefined as 7,000 troy grains. Since then, the grain has often been an integral part of the avoirdupois system. By 1758, two Elizabethan Exchequer standard weights for

12154-505: The two exceptions being New York and Alabama. The electronics and computer industries largely converted to metric standards as new technologies were introduced toward the end of the 20th century, also driven in part by a shift in manufacturing from the U.S. to countries in Asia with metric standards. Display sizes for screens on TVs and computer monitors are advertised and sold in inches (measured diagonally ), although most boxes also state

12272-422: The type of ounce is not explicitly stated, the troy system is assumed. The pound sterling money system, which was introduced during the reign of King Offa of Mercia (757–96), was based originally on a Saxon pound of silver. After the Norman conquest the Saxon pound was known as the tower pound or moneyer's pound. In 1528, during the reign of Henry VIII , the coinage standard was changed by parliament from

12390-515: The wave equation in atomic physics . Some unusual and non-standard units may be encountered in sciences. These may include the solar mass ( 2 × 10  kg ), the megaton (the energy released by detonating one million tons of trinitrotoluene , TNT) and the electronvolt . To reduce the incidence of retail fraud, many national statutes have standard definitions of weights and measures that may be used (hence " statute measure "), and these are verified by legal officers. In informal settings,

12508-421: The weight in vacuo of this standard shall be called the Imperial Standard Pound, and that all other weights mentioned in the act and permissible for commerce shall be ascertained from it alone. The first schedule of the act gave more details of the standard pound: it is a platinum cylinder nearly 1.35 inches (34 mm) high, and 1.15 inches (29 mm) diameter, and the edges are carefully rounded off. It has

12626-458: Was accidentally destroyed on a mission to Mars in September 1999 (instead of entering orbit) due to miscommunications about the value of forces: different computer programs used different units of measurement ( newton versus pound force ). Considerable amounts of effort, time, and money were wasted. On 15 April 1999, Korean Air cargo flight 6316 from Shanghai to Seoul was lost due to

12744-746: Was determined jointly by the standards department of the British Board of Trade and the Bureau International that 0.453 592 4277  kg was a better approximation, and this figure, rounded to 0.453 592 43  kg was given legal status by an Order in Council in May 1898. In 1959, based on further measurements and international coordination, the International Yard and Pound Agreement defined an "international pound" as being equivalent to exactly 0.453 592 37  kg . This meant that

12862-519: Was established for planning, coordination, and public education. The public education component led to public awareness of the metric system, but the public response included resistance, apathy, and confusion. In 1981, the USMB reported to Congress that it lacked the clear Congressional mandate necessary to bring about national conversion. Because of this ineffectiveness and an effort of the Reagan administration—particularly from Lyn Nofziger 's efforts as

12980-620: Was later defined in terms of 560.012 g (19.7538 oz). Bavarian reforms in 1809 and 1811 adopted essentially the same standard as the Austrian pound. In Prussia , a reform in 1816 defined a uniform civil pound in terms of the Prussian foot and distilled water, resulting in a Prussian pound of 467.711 g (16.4980 oz). Between 1803 and 1815, all German regions west of the River Rhine were under French control, organised in

13098-482: Was of 14 ounces of Colonha or 400.6 g (14.13 oz). The Portuguese libra was the same as 2 arráteis . There were also arráteis of 12.5 and 13 ounces and libras of 15 and 16 ounces. The Troyes or Tria standard was also used. A Jersey pound is an obsolete unit of mass used on the island of Jersey from the 14th century to the 19th century. It was equivalent to about 7,561 grains (490 g (17 oz)). It may have been derived from

13216-547: Was reformulated, refining the accuracy of its standards. The Metre Convention established the International Bureau of Weights and Measures (Bureau international des poids et mesures, BIPM) in Sèvres , France, to provide standards of measurement for worldwide use. Under the Mendenhall Order of 1893, metric standards, developed through international cooperation under the auspices of BIPM, were officially adopted as

13334-518: Was renamed the Zollpfund , but local pounds continued to co-exist with the Zollverein pound for some time in some German states. Nowadays, the term Pfund is sometimes still in use and universally refers to a pound of 500 g. The Russian pound ( Фунт , funt ) is an obsolete Russian unit of measurement of mass. It is equal to 409.51718 g (14.445293 oz). In 1899, the funt

13452-480: Was signed, a General Conference of Weights and Measures (CGPM) was established. The CGPM produced the current SI, which was adopted in 1954 at the 10th Conference of Weights and Measures. Currently, the United States is a dual-system society which uses both the SI and the US Customary system. The use of a single unit of measurement for some quantity has obvious drawbacks. For example, it is impractical to use

13570-570: Was similar to the Hawaiian bill. It would have established the International System of Units as the official units of measurement within the State of Oregon. The bill was in committee upon adjournment on July 6, 2015. During Lincoln Chafee 's 2016 presidential election campaign , he advocated for the switch to metric units. Following a widely panned debate performance and poor polling numbers, Chafee announced on October 23, 2015, that he would be ending his campaign. Many Americans have studied

13688-465: Was the basic unit of weight, and all other units of weight were formed from it; in particular, a zolotnik was 1 ⁄ 96 of a funt, and a pood was 40 fúnty . The Skålpund was a Scandinavian measurement that varied in weight between regions. From the 17th century onward, it was equal to 425.076 g (14.9941 oz) in Sweden but was abandoned in 1889 when Sweden switched to

13806-560: Was the result of both confusion due to the simultaneous use of metric and Imperial measures and confusion of mass and volume measures. When planning his journey across the Atlantic Ocean in the 1480s, Columbus mistakenly assumed that the mile referred to in the Arabic estimate of ⁠56 + 2 / 3 ⁠ miles for the size of a degree was the same as the actually much shorter Italian mile of 1,480 metres. His estimate for

13924-399: Was used between the 1350s and the late 18th century. It was introduced by the government of John II . The livre métrique was set equal to the kilogram by the decree of 13 Brumaire an IX between 1800 and 1812. This was a form of official metric pound. The livre usuelle (customary unit) was defined as 500 g (18 oz) by the decree of 28 March 1812. It was abolished as

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