Metrication (or metrification) is the process of introducing the International System of Units, also known as SI units or metric systems, to replace traditional jurisdictional measurement units. Although all US customary units have been redefined in terms of SI units, by 2018 the United States is one of only seven countries, including Myanmar (Burma), Liberia, Palau, Marshall Islands, Federated States of Micronesia, and Samoa which have not yet formally adopted the system metrics as heavy equipment and main sizes. However, both Myanmar and Liberia are reported to be essentially metrics, even without official laws in force, while Palau, Micronesia, and the Marshall Islands are all managed by the United States under the Freedom-Free Association.
Although customary units are used more frequently than metric units in the US, SI systems are widely used in areas such as science, medicine, the military, automobile production and repair, and international affairs. The post-1994 federal law also mandates that most packaged consumer goods are labeled both in customary units and metrics.
Video Metrication in the United States
Histori
abad ke-18
Soon after independence, thirteen United States used various units of measure, including Dutch units and English units. The 1789 Constitution gives Congress the authority to set standard measures, although it does not immediately use this authority to implement a uniform system.
In 1793, Thomas Jefferson requested French artefacts that could be used to adopt metric systems in the United States, and Joseph Dombey was sent from France with standard kilograms. Before reaching the United States, Dombey's ship was blown up by a storm and captured by pirates, and he died in captivity in Montserrat.
19th century
In 1832, the customary unit system was formalized. At the beginning of the 19th century, the US Coastal and Geodetic Survey, the government survey and mapmaking body, used the meter standard ("Meter Committee", French: MÃÆ'¨tre des Archives ) brought from Switzerland. Shortly after the American Civil War, the 39th United States Congress protected the use of metrics in trading with the Metric Act of 1866 and supplied individual states with a set of standard metric weights and metrics. In 1875 the United States established its commitment to the development of an internationally recognized metric system by becoming one of the seventeen signatory states to the Meter Convention, also known as the Meter Agreement. The signing of this international agreement ended the five-year meeting in which the metric system was redefined, perfecting its standard of accuracy. The Meter Convention established the International Bureau of Weight and Measure (International Bureau of des poids et mesures, BIPM) in SÃÆ'¨vres, France, to provide measurement standards for worldwide use.
Under the Mendenhall Order in 1893, the metric standards, developed through international co-operation under the auspices of BIPM, were adopted as the basic standard for length and mass in the United States. The definition of customary units of the United States, such as feet and pounds, has been based on metric units ever since.
The Utah Constitution of 1895, in Article X, Section 11, originally mandated that: "The Metric System should be taught in public schools of State." This section was revoked, effective July 1, 1987.
On July 4, 1876, Melvil Dewey (known for his Dewey Decimal Classification) entered the American Bureau of Metrics in Boston to sell rulers and other metrics. Dewey hopes to make his fortune sell metric inventories.
20th century
The General Conference on Weight and Size is the governing body for the modern metric system and comprises signatory states of the Meter Agreement. The General Conference on Weight and Size approved the latest version of the metric system in 1960 named Le SystÃÆ'¨me international d'unitÃÆ'Â Â © s ( International System Unit ) and abbreviated as i > 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 a metric system, unless it would have a detrimental adverse effect.
In 1968, Congress passed the US Metric Study, a three-year study of measurement systems in the United States, with an emphasis on metrication feasibility. United States Department of Commerce conducted research. The 45-member advisory panel consults and receives testimony from hundreds of consumers, business organizations, labor groups, producers, and state and local officials. The final report of the study concludes that the US will eventually join other parts of the world in the use of metric metrics systems. The study found that metric units have been implemented in many areas and that their use is increasing. The majority of study participants believe that conversion to metric systems is in the best interests of the United States, especially given the importance of foreign trade and the increasing influence of technology in the United States.
The US Metrics Study recommends that the United States adopt carefully planned transitions for the primary use of metric systems for a decade. Congress passed the Metric Conversion Act of 1975 "to coordinate and plan for increased use of metric systems in the United States". Voluntary conversions begin, and the United States Metrics Council (USMB) is established for public planning, coordination, and education. The public education component causes public awareness of the metric system, but the public response includes resistance, apathy, and sometimes mocking. In 1981, USMB reported to Congress that it lacked the clear congressional mandate needed to realize national conversion. Because of this ineffectiveness and the Reagan administration's efforts - notably from Lyn Nofigerer's efforts as White House advisor to the Reagan administration, to reduce federal spending - USMB was dissolved in the fall of 1982.
The end of USMB raises doubts that the metrics will actually be implemented. Public and private sector metrics slowed even as inter-country competitiveness and global market demand increased.
The American National Metric Council (ANMC) was founded in 1973 by the American National Standards Institute (ANSI) as a non-profit, tax-exempt organization to plan and coordinate metric activities across all sectors of the US economy. ANMC became a separate organization established in 1976. ANMC is intended to facilitate US metrics by maintaining a voluntary and orderly process that minimizes costs and maximizes benefits, and to provide information, forums, individual assistance, and other services to its customers. ANMC seeks to coordinate metrics planning from many industry sectors, unlike USMB, which is only trying to implement the policy set out in the 1975 Metric Conversion Act. After the formation of USMB, the ANMC committee submitted a conversion plan for the chemical sector and for the instrument sector. The sector conversion plan is then approved by USMB. From 1975 to 1987, ANMC held a series of annual conferences attended by many people. Subsequently, a series of National Metrics Conference, co-sponsored by the ANMC, the US Metric Association (USMA), the Ministry of Commerce, and the National Institute of Standards and Technology (NIST), were held from 1989 to 1993.
Congress includes a new push for US industry metrics in the Omnibus Trade and Commerce Act. This law changed the 1975 Conversion Law of 1975 and established the metric system as "the preferred weight and size system for US trade and commerce". The law states that the federal government has a responsibility to assist the industry, especially small businesses, because it voluntarily converts to a metric system of measurement.
This law requires most federal agencies to use the metric system in procurement, grants and other business-related activities by the end of 1992. While it does not require the use of metrics in the private sector, the federal government has sought to serve as a catalyst in the conversion of trade metrics, industry, and country trade. Exceptions are made for road and construction industries. The Ministry of Communications planned to require metrics units in 2000, but the plan was canceled by the 1998 TEA21 road bills. The US military generally uses a high-metric system, partly because of the need to work with the military of other countries.
Some members of Congress tried to ban the use of metric systems on federal highways in 1992 and 1993. These bills were unpopular in the House and failed before the vote.
Mars orbiter error
The use of two different unit systems led to the loss of the Mars Climate Orbiter in 1999. NASA assigns a metric unit in the contract. NASA and other organizations implement metric units in their work, but a subcontractor, Lockheed Martin, provides performance booster data to teams in pound-force-second units instead of newtons. The spacecraft is intended to orbit Mars at an altitude of about 150 kilometers (93 mi), but the wrong data causes it to drop to about 57 kilometers (35 miles), burning in the atmosphere of Mars.
21st century
Efforts toward national metrics are based on the premise that industrial and commercial productivity, math and science education in the US, and the competitiveness of its products and services in the world market will be enhanced by adopting a metric system. Gerard Iannelli, director of the US Metrics Program, gave an opinion that Americans have so far not done so because of the effort required to "translate" from common units to metrics when the two measurements are not displayed. He also cites what he considers to be an ineffective effort in public education and awareness.
In June 2010, NIST called for an amendment to the Fair Packaging and Labeling Act that would allow option manufacturers to voluntarily label their parcels only in metric units, rather than be labeled double with the units and units of common US metrics as they are currently required. The goal of this change is to encourage the labeling of metrics, leading to greater approval of US labeling legislation and simplifying domestic and international trade. NIST's Program Coordinator Elizabeth Gentry added that the proposed changes were "in response to requests from US producers and consumers", especially that "producers want to control the quantity of real estate content is limited to the packaging."
On December 31, 2012, a petition was made in the White House petition system, petitioned the White House to "Establish a standard Metric system in the United States, not the Imperial system." On January 10, 2013, the petition collected more than 25,000 signatures, exceeding the threshold required to require the Obama Administration to formally respond to the petition. Patrick D. Gallagher, director of the National Institute of Standards and Technology, gave a formal response stating that customary units are defined in the metric system, thus making the nation "bilingual" in terms of measurement systems. Gallagher also said that using a metric system is a choice made by individuals.
In early 2013, State Representative Karl Rhoads introduced the HB36 Bill to the Hawaii House of Representatives seeking to establish a mandatory metric system in his country. Called "Relating to the Metric System", the bill stipulates that the law will come into force on 1 January 2018. In June 2014, the HB36 Bill did not receive sufficient support and was considered dead. If the bill becomes law, Hawaii will be the first country to introduce a broad-scale metric system.
In January 2015, Oregon State Senator Brian Boquist, at the request of David Pearl's metric enthusiast, proposed Oregon Senate Bill 166, which is similar to the Hawaii bill. This will establish the International System of Units as the official measurement unit in the state of Oregon.
Maps Metrication in the United States
Current use
Daily life
Most Americans have studied common metric units in schools. Also, new units introduced by engineers, such as kilovolts, megabytes, megapixels, and kilotons and megatons of TNT, are generally formulated in terms of power 10.
The use of SI derived units is widespread for many applications. The residential power power plan uses kilowatt hours, the luminous flux of the lamps is determined in lumens rather than candlepower.
The K is commonly used to indicate "thousand" (for example, "He made $ 80K"), although this is not consistent with the lower case "k" in SI. This use largely replaced the letters "G" (for "big", used almost exclusively for money) and the Roman numerals M normally used for "thousand" before the 1960s; actually, "M" has now shown "million" (for example, "budget $ 32.5 million").
Weather
TV and radio weather reports are given in degrees Fahrenheit instead of Celsius for dew and air temperature, miles per hour for wind speed, inches of mercury for atmospheric pressure (milibar is only used when reporting tropical phenomena like hurricanes), and other customs. units. In some northern border states, temperatures are depicted in Fahrenheit and Celsius for the benefit of Canadian cross-border audiences.
NOAA Weather Radio broadcast from the National Weather Service at Twin Cities of Minnesota provides local temperature reports in Fahrenheit and in Celsius, as does the WXL57 weather radio in Des Moines, Iowa.
Consumer and retail
Some US consumer products have a rounded metric size. This appears to be increasing due to the nature of manufacturing, distribution, and international sales. Many items are produced in a number of round metrics and some manufacturers prefer to display metric quantities first or more prominently (for example, Crest Glide dental floss available in 35-, 40-, and 50-meter packs).
Probably the most common metric item sold is a two-liter bottle. Several supermarket chains also make their brand soft drinks available in 3 liters. The 1 and 0.5 liter soft drink containers (and more recently the 1.25 liter bottle) are sometimes sold together with 12 fla, 16 fl oz, 20 fl, and 24 fl oz (355, 473, 591 and 710 mL).
A half liter bottle of water (16.9 fl oz) almost replaces the size of 16 ounces. 700 mL (23.6 fl oz) and a one-liter size are also common, although 20 fl, and 24 size sizes remain popular, especially in vending machines.
Attempts to sell 3 or 4 liters of milk jug instead of gallon (3785 L), mostly unsuccessful, and such bottles are rarely seen in the United States. Milk remains sold in a gallon binary division, with half pints, pints, pints and half a gallon being the primary measure.
Shampoos, mouthwashes, and dental floss have gone on sale in metric sizes. PowerBars and similar products are always sold (but not marketed) by grams.
Nutrition food labels typically report portion sizes in both systems but only include metric values ​​(g or mg) for individual nutritional breakdowns.
Alcohol
Wine is sold in a standard 750 mL bottle, as in other parts of the world. A fifth of liquor, once a fifth of a US gallon, or 757 mL, is now generally 750 mL, although it is still referred to as "a fifth". Beer is sold in denomination of fluid ounce. Regulations are governed by the Tax and Trade Bureau of Alcohol and Tobacco which controls the size of the permitted containers. Unlike non-alcoholic drinks, most alcohol products are not required to carry unit conversions on labels.
Food is not packaged
Fruits and vegetables are loosely close to the general price per pound or per item. In supermarkets and steaks, cuts of meat are sold in ounces and pounds. Goods that are sold freely do not need to carry unit conversions.
FPLA
Since 1992, the federal FCLA (FPLA) Act has required most of the consumer goods packed to be labeled both in customary units and metrics. Some industries are involved in attempting to amend this law to let manufacturers only use metric labeling. Forty-eight US states have adopted laws that allow labeling only in metric units, two exceptions are New York and Alabama. New York reportedly examined the shift to allow labeling of metrics in 2008, but has not done so in 2009. According to the European Community Directive 80/181/EEC on December 20, 1979, the EU will allow the dual-unit labels to appear on the product only until December 31, 2009 , but problems with metrics in the UK forced the EU to leave this deadline.
Waiting for the deadline for EU metrics metrics, the amendment of the FPLA to enable the labeling of metrics alone in the US will allow manufacturers, both importers and exporters, to avoid significant costs resulting in two different types of packaging labels. A bill to allow the labeling of metrics at the federal level will be introduced in 2005. A significant opposition from the Food Marketing Institute, which represents US merchants, has delayed the introduction of the bill. FMI expressed fear that the law to allow only-metric labels may also somehow mandate resizing the packaging to round metric size (a well-executed process), and this could require costly renovation or replacement of existing display cases. A compromise has been suggested in which manufacturers in the US and the EU may choose only-metric or dual-unit labeling, but this idea has been dimly seen by EU negotiators.
Electronics
The electronics and computer industries were largely converted into metric standards because new technologies were introduced towards the end of the 20th century, also driven by manufacturing shifts from the US to Asian countries with metric standards.
TV and computer screens are advertised and sold in inches (measured diagonally), although most boxes also state the size in centimeters.
The original / 4 inch (635 mm) connector connector dates back to 1878 and is still seen used in audio equipment and electrical instruments. In many ways, it has been replaced by a 3.5 mm connector or 2.5 mm headset, which is common on older phones.
While the initial floppy disk has a nominal packet size of 5 1 / 4 inch (about 130 mm), the nominal nominal "3 < soup> 1 / 2 inch "the actual disk is 90 mm. CDs and DVDs are 120 mm in diameter, but their size is seldom mentioned; Mini CDs are sometimes called CD 80mm.
The size of the computer fan is exclusively called by the metric unit (120 mm or 80 mm fan, for example), while the hard disk drive and CD drive width are regular sizes, usually 3 1 / 2 inches and 5 1 / 4 inches, respectively.
Consumer size photography films are generally sold in standard 35 mm (24x36 mm negative), although the size of the print and large format films are specified in inches. The size of the digital camera sensor is measured by means of an archaic denoting an inverted inverse fraction representing the equivalent vidicon tube diameter. For example, the 1/1.6 "sensor is larger than the 1/2.5" sensor. However, the lens is marked by focal length in millimeters (eg, the average human field of view is a lens with a focal length of 50 mm for 35 mm film).
Clothing
Clothing is measured in inches, not centimeters. The size of American shoes is measured on different scales for children, men, and women, but all sizes come from inches. Major multinational clothing brands including Nike, Adidas, Hanes, and Levis often sell the same inventory worldwide, with labels containing SI and custom units in addition to the symbol of clothing treatments and instruction in many languages.
Bedding
The size of the mattress is based on a king, queen, double, single scale.... This size comes from inches unlike most other countries that use similar scales but are sized for the addition of metrics. The FPLA requires that bed sheets be declared a type of bed intended for other than dimensions in centimeters and inches. The FPLA also mandates multiple scales on many other woven items such as towels.
Construction
Of all industries, construction has adopted the fewest metric units. The timber dimension comes in nominal nominal cross-sectional sizes and the length is given in feet. Although modeling codes - such as the International Building Code - provide information in customary units and metrics, locally developed building code amendments and zoning codes often provide exclusive customary units. Due to Canada's proximity to the US, a common unit problem persists. The tendency in this construction is similar to Japan, another stated country where traditional construction still uses Japanese units that precede metrication. However, blueprints typically indicate measurements using decimals (eg 9.2 ft); because the foot is not divided into a tenth on a US measurement tape, builders are generally forced to make conversions in places that are often inappropriate. In the previous example, 9.2 ft equals 9Ã, ft 2.4 inches; slightly more than 9Ã, ft 2-3/8 on the United States measuring tape, although this error rate is usually not significant for this application.
Flights
Aircraft height for air traffic control and related purposes is measured in feet in the US. In fact, most of the world has been using the foot for the height of the flight since the end of World War II (a few meters before 1945 in all European countries except Britain), with notable exceptions from China, North Korea, and many CIS (former Soviet) countries. For example, a plane on a long flight, even if its starting point or destination is not located in the United States, may use a nominal 36.000 foot roaming altitude, using an international-level flight system (Flight Level 360 in this case). In 2011, Russia shifted from metric flight level to foot-denomination at high altitudes to eliminate the need for adjustment when it crossed into or out of its airspace.
Commercial flights
Frequent flyer programs from commercial airlines in the United States are generally managed using miles. This is likely to continue; In fact, some international airlines using miles turn to miles or use both, to simplify the exchange of miles with US airline partners (Aeromexico switches from kilometers to miles, and Varig from Brazil has been using miles since the program was named "Smiles"). Airplane speed is often measured in knots and at the foot altitude in many countries.
For domestic and international routes, US airlines set baggage sizes and heavy restrictions in terms of custom units. In contrast, international airlines flying into the US often limit baggage to metric sizes.
Temperatures in flight related weather reports are given in degrees Celsius in the United States.
To perform the suitcase, the Transportation Security Administration limits the liquid to 3.4 ounces of liquid (100 mL). Initially, the agency plans to limit up to 3 ounces but turn it into 3.4 oz/100 mL after pressure from the EU.
Education
Most students are given some degree of introduction of metric systems in primary, secondary, and high schools, but the emphasis varies. The main instructions center on the concept of force 10, related prefixes, and conversions from one prefix to another. The units of length, volume, and mass are usually introduced by comparison with ordinary objects. The metric system is not reinforced far outside the classroom due to the lack of use of popular metrics. As a result, while students can understand some of the underlying concepts of metric systems, they do not always have an intuitive meaning of unit value.
In science education, students predominantly use metric measures in experiments and equations, allowing those interested in science to become more familiar with the metric system. The science class is a requirement for a bachelor's degree in the US that ensures the most educated person has some familiarity with the metric system. In higher education, the metric system is universal for classes in science (see below), except for exercises designed to describe complex conversions. Some non-science textbooks in the US use only metric systems without providing a conversion to promote metrics.
Electricity and energy
There is no US general unit for electric current, potential difference, or load because this concept was developed after the international application of metrics in science. The units of ampere, volt, ohm and coulomb metrics are the units used. The term SI hertz has replaced the term cycles per second as a frequency unit.
Energy is often measured in watt hours, BTUs, therms or calories than SI joules. Commercial and commercial energy use is measured and billed in kilowatt hours, kW Â · h, as in most metric countries. Forced measurements regularly using pounds instead of newton SI; torque is measured in pound-feet. Fuel prices are mostly given in customary units, such as dollars per gallon, barrel, thousand cubic feet, or tons (short or long). Heating, cooling, and combustion are often measured in BTU per hour or ton cooling and powerplant efficiency is often measured by "heat level", in BTU per kW Ã, Â · hour. Engine rated power, electric motors, and power steam turbines are often measured by horsepower. The output of a power plant is generally expressed in megawatts.
Financial services
The United States is one of the first countries to adopt the decimal currency. Until 2001, US stocks traded in dollar binary splits ( 1 / 2 , 1 / 4 , 1 / 8 ) based on an eight-year-old Spanish piece, but the US Securities and Exchange Commission ordered shares to move into dollars and cents. However, Treasury Notes and US Treasuries continue to trade in 32nds, 64ths and 128ths of a dollar. Some commodity market prices are quoted in customary units (such as oil barrels, troy ounce gold, pork pork frozen, etc.). The federal government reports international production figures in metric units (eg, wheat in metric tons) but in bushels for domestic production figures.
Firearms
The US uses inches and millimeters for caliber on civilian firearms and law enforcement. Historically, rounds of ammunition designed in the United States are denoted by their caliber in inches (eg,.45 Colt and.270 Winchester.) Two developments alter this tradition: the large number of different cartridges using identical caliber and international arms transports bring the caliber metric to United States of America. The first causes the bullet diameter (not the caliber) often used to describe the rotation to distinguish a similar spin. A good example is.308 Winchester, which fired a.30-caliber projectile equal to 0.30-06 Springfield and.300 Savage. Sometimes, the caliber is just a number close to the diameter of a bullet, such as.220 Swift,.223 Remington and.222 Remington Magnum, all of which have.22 or.224-inch-diameter (5.7 mm) bullets.
The second development is a caliber metric introduced to the United States. 6mm and 7mm caliber rifles are very popular like 9mm caliber pistols and 10 mm caliber. These caliber metric rotations are portrayed by their metric caliber, like the 7mm round of Magnum Remum which is very popular or has the diameter of their bullets converted to inches, as well as the very popular.243 Winchester. Sometimes, a round of caliber inches designed by AS is expressed in metrics as well.
The US military, which reflects its need to ensure interoperability with its NATO allies, uses metric measurements for almost all caliber weapons, even when for caliber originating from or derived from different measurements (eg 7.62 mm rather than 0.308, or 5.56 Ã, mm not 0.223). However, a civilian rifle flagged for.223 Remington can load 5.56mm military ammunition but does not fire it safely because 5.56mm NATO ammunition is loaded to create room pressure greater than.223 Remington. The controversy exists whether this is true for civilian rifles hijacked for.308 Winchester fired a 7.62x51mm NATO military ammunition. Major handloading manuals in the US use the common US units for all related measurements including bullet diameter, cartridge overall length, maximum powder weight, speed and pressure, even with complete metric rounds designed entirely by Europe.
Gems
Gems and pearls are sold in metric rust.
Manufacturing
Manufacturing globalization has led to the adoption of extensive metric standards, although this is not yet universal. After a period in which automobiles are assembled with general fasteners and metrics in each vehicle, the car is now universally built with metric sections. The car engine was once named after their displacement in cubic inches. For example, the Chrysler "426 Hemi" engine will be described as 7 liters in modern terminology. Technical publications by industry publishers and American automakers often provide machine shifts in cubic inches as well as cubic centimeters (equivalent to milliliters), or liters. For example, the specification for Dodge SRT-8Ã, 6.1Ã, L Hemi states displacement as 370 cubic inches (6,059Ã, cc).
Military
The US military uses metric measurements extensively to ensure interoperability with allied forces, particularly the NATO Standardization Agreement (STANAG). Land forces have measured distances in "klicks", slang for kilometers, since 1918. Most military firearms are measured in metric units, starting with M-14s introduced in 1957, although there are some exceptions to inheritance, such as.50 caliber weapons. Armaments are usually measured in pounds. The caliber of heavy weapons is measured in millimeters. Military vehicles are generally built to metric standards. The exception is the US Navy, whose weapons are measured in inches and whose subsea fleet measures distances in kilovards, depth as "feet", and speed, in some cases,. The Navy and Air Force continue to measure distances in nautical miles and speeds at knots; these units are now accepted for use with SI by BIPM. Furthermore, in NATO military aviation countries use legs for flight height, as they do in civil aviation.
Illegal drugs and controlled substances
Illegal drugs and controlled substances are often measured in the number of metrics. Federal law prohibits them from defining punishment in metric mass.
In daily use in its subculture, marijuana is sold using a combination of American metric and customary units. On a small scale, the basic units are grams (or fractions), but for order fractions greater than the ounces and pounds used generally start at 1 / 8 ounce, which is often defined as 3.5 grams and is referred to as "eighth". The power of LSD tabs is almost always expressed in micrograms. The term "kilo" is used quite commonly by them in law enforcement to describe the amount of drugs (in kilograms) confiscated during a drug bust. One kilo of illicit drugs (especially cocaine) is often referred to by the term "key" slang.
Science
In science, the use of metrics is essentially universal, although additional specialized units are often used for specific purposes in various disciplines (such as parsecs and light years in astronomy), consistent with worldwide usage.
Earth science, such as hydrology and geology, continues to use customary units for field surveys, both because of the legacy of decades of data collection and the need to work with the construction industry, which has not yet adopted the metric system. American irrigation engineers, for example, speak with legs and cubic feet per second, while their Australian counterpart will refer to gigaliters and cubic meters per second.
Meteorologists extensively use metric and customary units. The METAR reporting system used in the United States is different from that used by the World Meteorological Organization (WMO) in wind speeds delivered in knots (not meters per second), equivalent rainfall in one hundredth of an inch, and altimeter setting in the common inch of mercury (not hectopascal). Furthermore, the temperature is reported in degrees Fahrenheit but converted to Celsius when encoded in the METAR report. Most synoptic observation diagrams are expressed in SI units, except for the wind speeds mentioned above, which must be converted for calculation purposes. The upper air temperature chart usually uses the Celsius scale (the frozen line is essential at lower atmospheric levels in determining the precipitation type) while the potential temperature graph uses kelvin; both of which are in line with international usage. The atmospheric vorticity is usually measured in full rotation per 100,000 seconds (rough metric days) but not using recommended SI radians.
The National Weather Service and public forecasts of broadcast TV/radio, however, are given almost exclusively in customary units: Fahrenheit degrees for temperature and dewpoint, one inch of rain or ice and an inch of snow (less than an inch often indicated by an informal fraction or term such as "dust" when very low), inches of mercury; and for wind speeds, miles per hour, except in oceanic estimates, where knots are used and wave heights are measured in leg units. Actual hail and snowfall and its depth in the soil are measured in tenths of an inch, with actual rainfall within a hundredth, and an increase in ice either in fractions or decimals. The size of hail is usually reported without a fixed-size unit; they are instead compared to familiar round objects or round balls (eg the size of a dime or a golf ball). The cyclone reading barometer is usually given in millibars (mb), equal to hectopascal (hPa), or ten times kilopascals (kPa) used in neighboring Canada; the use of inches of mercury in such applications is rapidly declining.
In early 2007, NASA announced that it would use a metric unit for all operations on the lunar surface after returning to the Moon, then projected for 2020. However, NASA's birthday program was canceled in 2010.
Medicine
Medical fields use predominantly metric units. When interacting with patients, certain data, such as their height and weight, are presented in customary units.
Pharmacology
Both prescription and nonprescription doses are always measured in SI systems with the most common units being milligrams. Smaller doses use micrograms. Because SI prefix? (mu) is not well known among many Americans and it is not available on most medical industry keyboard using mcg abbreviation to show microgram.
For vitamins, the amount of nutrients is given in gram denominations or international units of the WHO standard, known as IU.
The size of the pill container, when occasionally discussed, is largely discussed in the form of fluid drama, although most also contain cubic centimeters and sometimes liquid ounces on the specification.
For a long time, the doses of the liquid drug were shown in milliliters and units of teaspoons and tablespoons, which were standardized at 5 and 15 mL. However, many people speak colloquially referring to a small spoon in a tool that is designated as a teaspoon and a large spoon as a tablespoon. After a major analysis in 2015, it was found that inclusion of tea/spoon dose was likely to encourage some people to use uncalibrated kitchen utensils as gauges. Due to this and reported confusion with the abbreviations of TSP and TBSP, the FDA now recommend doctors and pharmaceutical manufacturers to speak (and label their products) with only milliliter dosing. To assist in this transition, the FDA encourages drug makers and pharmacies to include disposable liquid cups with liquid medicines.
Concentration and Blood Work
Drug dose guidelines are determined in terms of milligrams per kilogram. The exact metric unit used by health care professionals in the US sometimes varies from country to country. For example, US diabetes mellitus patients measure their blood sugar levels in milligrams per deciliter (such as cholesterol and other blood concentrations), whereas most other countries use millimoles per liter. The American blood glucose meter has the ability to switch between the two.
Blood and urine samples were taken by milliliters. Intravenous (IV) therapy is given by milliliters. To avoid confusion, 1 liter bag is listed as 1000mL.
Height and Weight
Such high anthropometric data can be recorded in centimeters. Body mass index (BMI) is expressed in kg/m 2 , although it can be calculated from pounds and inches. Even if medical practice takes high and heavy data in terms of SI units, it is almost always discussed with patients in terms of custom units. Exercise is usually discussed with the patient in terms of miles of walking. The intake of sugar, sodium, and other nutrients is usually discussed in grams and milligrams.
Use among veterinarians varies, but due to heavy emphasis on public interactions, the weight of the animal (eg, for cats or dogs) is almost always recorded and reported in pounds and ounces. Use in veterinary education hospitals, on the contrary, is more favorable to SI units.
Dentistry
Measurement of dental/movement location and periodontal graph (gum health) are within millimeters.
​​â € <â €
Accurate sound level measurement devices are not found until after the microphone or in this case after the proliferation of SI systems in physics and internationally. Therefore, although certain information on sound pressure can theoretically be evaluated in units of pounds per square inch (PSI), this is almost never done. In contrast, the decibels (dB) used internationally are the most common. In some cases where there is a desire for a non-logarithmic scale, a decill-related cone scale is used. For example, the noise level of a tool is usually assessed in terms of sone output. Hearing protection should be labeled in the case of decibel reductions with more detailed graphs showing decibel reduction at the given hertz frequency.
Sports
Americans are often exposed to metric units through coverage of international sporting events, especially the Olympics.
While the Olympic Trials tracks and field is always done within a metric distance, in order to duplicate the selected competition the designated athlete, the National Championship turned into a metric in 1974. However, USA Track & amp; Field (USATF) continued to count the national championships in high jumps in US customary units until 2002. The National Athletic Association Association (NCAA) transferred its measurement system at the National Championship level in 1976. The last resilience was the National Federation of State Association of Colleges (NFHS ) manages a high school sport, which switched to metrics in 1980.
That said, the US track-and-field competition usually runs in multiples of 400 meters, which is roughly in keeping with traditional mile-based lengths. At the Olympics, athletes run 1500 meters instead of 1,600 meters.
Running a race in the U.S. usually runs within a metric distance (for example, runs 100 meters and 5K (5 kilometers)), although mile distances remain popular. But even 5 and 10 kilometer races most often have mile markers on the field, and no kilometer markers. Remote racing is often measured in kilometers, although there are exceptions (generally 10 miles race). The Marathon is referred to as a 26,219 mile long race (the official standard marathon distance originally in English units - 26 miles, 385 yards) rather than 42,195 km. Ultramronons are measured in miles or kilometers, with little standardization.
Although the Olympics and US track events have been a metric for many years, it's still common for sports commentators to provide conversions to help American audiences understand measurements.
The measured distances as used in events such as shot put, high jump, and throwing discs, however, are often in feet and inches, except at national and international levels. By 2017, the High School Athletics Association in Florida will be the first to fight this trend and use metric measures for field events. The size of the field and the courts for the most popular team sports such as football were originally set in non-metric units. This is reflected in American football, where the playing field is divided into yards, and many important statistics are measured in yards. Similarly, dimensions for all baseball parks, basketball courts, tennis courts and ice hockey arena are provided at the foot, a golf course in the yard, a race car track within miles (or fractions thereof), and horse racing over long distances. The length of auto racing in the US is generally set in miles. On the other hand, some sports equipment, such as skis and poles, are sold in metric units.
A new American football game was attempted in metric in 1977. The trend failed to gain a foothold.
Bicycles, especially at high ends, are increasingly sold and sized in metric units. For example, frames depicted as "21 inches" in the past are now often labeled as "53 cm" frames instead. Some bicycle wheels are labeled in a metric as "700c" for a 700mm diameter road bike tire, but mountain bike wheels are still often sold in inches (26, 27.5 or 29 inches)
The dimensions of the public swimming pool are 25 yards, 25 meters, and 50 meters. Middle schools and NCAA perform 25-page competition. USA Swimming (USA-S) swimming in both metric and non-metric pools.
In the Ultimate Frisbee game, the 175g flying disk is considered a standard sport.
The Mid State Trail (Pennsylvania) long distance trail has been using metric units exclusively in its trail guides since 1973.
USA Weightlifting uses a metric unit to measure weight.
Transportation
Highway speed limits are installed in miles per hour and distances are displayed in miles, yards, or legs, although some dual mile/km signs can be found, most of which are left from pilot projects that are no longer supported. One exception is Interstate 19 in Arizona, which is almost completely signed in metrics, except for speed limit signs. However, the signing on this road was changed back into custom units as it was replaced. Another exception is the toll section of Delaware Route 1, which uses a mileage-based system, in anticipation of a mid-1990s conversion in the US to a metric system, which did not occur. The distance was initially signed within kilometers, but has since been replaced with miles in 1995 and the standard mile-marker in 2003. Fixed-out metric numbers start at Dover Air Force Base to the north to Interstate 95.
The 2000, 2003 and 2004 editions of the Manual on Uniform Traffic Control Equipment are published using Metrics and American Customary Units. Metric signs, including the signs of speeds in kilometers per hour, are shown in the manual even though they are not usually used on the road and there are no fixed plans for metrics. For visual differences, regulatory and advisory metric velocity signs have dark circles around the numbers followed by "km/h" and other rule signs have yellow plates that read "METRIC" black on top of the main signs. Metrics marks and metric measurements have been removed for the 2009 edition and replaced with the metric conversion table attachment. This is very different from the position in the (mostly metric) United Kingdom, where the metric road signs are prohibited by law (except for those who indicate width and height restrictions, which include metric and imperial units).
New signs on the state highway on Kaua'i island in Hawai'i also cover distances within miles and kilometers. Distance markers along the highways on the Island of Hawaii will show both units whenever all kilometers match approximately by the whole mile (eg, 5 mi/8 km). In Houston, Texas, many speed limits have km/hour marks below the MPH mark. It is located near both airports (Bush Intercontinental and Hobby) and at Texas Medical Center. The US Puerto Rico region typically uses American-style signs (MUTCD) with metric measurements on the highway, featuring kilometers and kilometers within miles, but the speed limit marks in miles per hour. Maine Turnpike has metric measurements on road signs in addition to customary measurements, in part to help large numbers of Canadian tourists who visit the coast of Maine.
The first signs in metrics in the United States were posted on February 12, 1973, at Interstate 71 in Ohio.
Gasoline and diesel are sold by US gallons, and fuel economy is valued in miles per gallon (MPG). Metric units are kilometers per liter but, with some exceptions, such as Denmark, metric states use inverse units, l/100 km, rather than km/l. The stations at Point Roberts, Washington, a short, non-contiguous peninsula that is accessible from other Washington states simply by crossing into Canada, sells its gasoline from a calibrated pump to dispose of the liter. Gasoline is distributed in liter in Puerto Rico. Crank car oil is sold by quart, antifreeze by gallon, brake fluid by ounce (liquid), and air conditioner by ounce (mass). Windshield wiper blade measured in inches.
Domestic airlines are assigned heights in the legs and measure the speed at knots. The ocean chart shows depth in the depa and uses the nautical miles for distance. (A one-minute crossbow on the radius of the earth at sea level is the standard for one nautical mile until about 1929. The sea mile is now defined as exactly 1,852 meters.) The railroad uses a standard 4 foot span 8 > 1 / 2 , as is most of Europe (where it is expressed as 1,435 mm).
The Federal Federal Vehicle Safety Standard 101, which regulates vehicle control and display, allows the speedometer to display miles per hour (MPH) or MPH and km/hr. In practice, most US market vehicles have miles odometers and speedometers are labeled double by mile-per hour as the main calibration. Some 2000s Buick has a single speed gauge with buttons on the instrument panel to change the scale between MPH and km/h. Other vehicles have a digital speedometer that can be set to read speed either in MPH or km/hr.
Another common unit of speed is meters per second (m/s), which is used primarily for elevators and cable cars. Odometers are allowed to record miles or kilometers, but must be clearly labeled about which units they record.
Tire inflation for passenger cars is usually around 30 pounds per square inch (psi) or 207 kilopascals (kPa). This is shown on the tire next to the equivalent metric. Post-model 2006 regulations also require "International Information Ban and Loader" stickers that provide capacity in SI units followed by adat equivalents.
Hybrid unit
Some measurements are reported in units derived from customary units and metrics. As an example:
- Heat rate from power plant: BTU/kWh
- Federal federal car emission standards: grams per mile
- Caffeine in beverages: milligrams per ounce
- The standard method for measuring tires combines millimeters for the width of the tread but uses an inch for rim diameter.
- In lighting, the bulb uses eight inches for the diameter of the bulb and the full inch for the length of the fluorescent tube, whereas the socket is always in millimeters (eg, the standard "Edison intermediate screw" is E26). In the recently introduced Christmas lights, however, millimeters are often used with small spherical balls (G30 and G40), and with miniature LED sets, where the standard T1Ã,¾ ( 7 / 32 -inch tube) sometimes called M5 (5mm miniature, not to be confused with M5 thread).
For properties that are understood recently, such as those related to electricity, there is no traditional unit; international units are always in use, often combined with US customary units. One of the many examples is in Table 8, chapter 9, of the National Electrical Code Handbook (8th ed.), Where the resistance of the conductor per unit length is given in ohms per thousand feet.
Other units are based on custom units, but use the power of ten factors and the prefix of metrics. For example, the distance to the target for a US submarine is expressed in kiloyards rather than some combination of miles, yards, and legs. The length of the phone's transmission line and the loop distance are measured in kilofeet. In some areas of civil engineering (especially structural engineering), and architecture, large loads and strengths (such as building weight or number of loads applied to columns) are measured in kips (kilopounds or 1000 pound-force) instead. short ton-force (2000 pound-force), which is used in virtually all other non-metric industries in the United States, as well as common use among the public, when faced with great power values.
Cultural impact
The continued use of US customary units has led authors to speculate in future fictional adoption of metric systems. Many authors assume that the United States and the human race will generally use metric units; however, others have assumed the continued use of US customary units or have forgotten to take metrics into account. Writers sometimes use customary units simply because American readers and observers will understand their size; at other times, they are only used by chance. The 1966 show Star Trek , for example, originally used the US customary unit despite some Earth Earth origins and settings in the 23rd century. Then, starting with "The Changeling", metric sizes are used, though inconsistent. Then the sequels of the show, such as Star Trek: The Next Generation, and Star Trek: Enterprise (set in the 22nd century), use the exclusive metric system.
Both metrics and attitudinal systems in the US against metric systems are jabs fun targets in shows like The Simpsons , Futurama and The Big Bang Theory . The Saturday Night Live sketch called "Decabet", released at the height of the metric movement, bombarding different metric measurements by introducing a new alphabet consisting of only ten letters.
In the 1994 film Pulp Fiction Vincent Vega (John Travolta) told Jules Winnfield (Samuel L. Jackson) that "Europe is slightly different", for example in Paris they do not call it "Quarter Pounder with Cheese" but "Royale with Cheese" as "they have a metric system, they do not know what Quarter Pounder is." Later, Jules praised the intelligence of one of their victims, after he correctly guessed that the use of the French metric system was precluding the term "Quarter Pounder."
Popular Science ' s September 2003 edition lists NIST's "Metric System Advocate" in the "Worst Works in Science" list.
See also
References
External links
- United States and System Metrics (LC 1136) nist.gov Archive.org
- System Metrics in the United States
- A Metric America: The Upcoming Time Decision at nist.gov Archive.org
- Metric Conversion Act of 1975 on nist.gov Archive.org
- www.us-metric.org - U.S. Metric Associations (mirror link)
- Means Pak Metric satire about conversion (not) to metric unit. One of the highest scoring submissions to the Oracle Internet. Originally written by Jim Palfreyman in October 1991.
- Weight & amp; Size
- An example of roadigns metrics in the US. Site
- www.metrication.usÃ, - Metrication.us at Archive.org
- www.metric4us.comÃ, - Metric 4 US! site
Source of the article : Wikipedia
0 Comments