Even the US military is almost entirely metric. The United States is the last remaining industrialized nation with no formal commitment to going metric. America's position is causing unnecessary isolation. It's an impediment to trade and puts the United States at a disadvantage. Not being metric-fluent can hamper collaboration and communication across borders. And it's not just annoying, but can add real costs.
For example, many US manufacturers need to make two kinds of products for every item — one for here and one for there. Foreign manufacturers also have to modify products just for the US market or decide that maybe it's not worth the bother. The US is one of the few holdouts not on the metric system. Islands in a Metric World, Since this map was made, the US hasn't gotten any allies on its lonely island. Being stuck with US customary units is bothersome, but a culture that does half and half is even more problematic.
Every time someone or a computer converts a unit from one system to another, there's a potential for error. Proponents of the metric system love to collect conversion-error horror stories. Another big problem is in medicine. Some 3, to 4, kids end up in the ER each year because of wrong doses from a caregiver.
And unit confusion is partially to blame. Consider a simple cup for dispensing liquid meds, below — it has both teaspoons and milliliters on it. That, a s Bridget Kuehn reported , makes it easier for people to give the wrong dose. And because 1 teaspoon just happens to be equal to 5 milliliters, it's likely that a wrong dose would be off by a factor of five. Kuehn, BM.
Published online May 21, Both the Institute for Safe Medication Practices and the US Centers for Disease Control and Prevention are encouraging manufacturers and the pharmacies to use only the metric system on over-the-counter meds for these reasons.
But they aren't requirements, just suggestions. Another problem with a dual-measurement US is that some professions are speaking a different language than the rest of the culture. Experts regularly talk about the need for more qualified American workers in science, technology, engineering, and mathematics STEM.
But because metric isn't learned from birth, students must first learn a foreign language — the metric system — before they can learn science or engineering or become part of the medical community. Others elect a prime minister. Some people walk on a sidewalk while others travel on a footpath. Even measurements vary by country!
In some places, we measure distance in miles. In others, we use kilometers. One mile is about 1. They are part of different measuring systems. The mile is part of the Imperial System. On the other hand, the kilometer is part of the Metric System. Have you ever heard of the Metric System? The Metric System has many units of measurement. Meters measure length, grams measure mass , and liters measure volume.
Adding a prefix to a unit of measurement makes the unit larger or smaller. To do that, we have to know there are 5, feet in one mile. Then, we need to remember that twelve inches make a foot. In the Metric System, you just have to remember the prefixes. Here are a few of the most common prefixes and what they stand for:. How does this work? If you add kilo- to a unit of measurement , that makes it one thousand times bigger.
A kilogram is one thousand grams. A kiloliter is one thousand liters. A kilometer is… You guessed it! One thousand meters. You can also make measurements smaller. If you add centi- to a unit , it makes it one-hundredth of that unit. Have you ever heard of a centimeter? Likewise, a centigram is one-hundredth of a gram, and a centiliter is one-hundredth of a liter.
There are many other prefixes we can use in the Metric System. So in this case, a more precise conversion is warranted:. Centerline markings shall be placed on all paved urban arterials and collectors that have a traveled way of 6. This is a soft conversion because the actual dimension did not change, but is merely expressed in different units. The Oxford English Dictionary lists metrication as the preferred form.
Its earliest citation is a 29 November Times article quoting J. Dunworth, Director of the National Physical Laboratory :. Earlier this year the National Physical Laboratory sought the guidance of the editor [sc. The modern tendency is to use -ize, -ization in forming new words rather than -ate, -ation.
It seems to me that either metrication or metricization could be used. The imperial gallon, quart, pint, etc. For a good look at these issues, read J. Since , US customary units have been defined in terms of the SI.
For details, read the Mendenhall Order and the Refinement of values for the yard and pound , as well as the Adoption of the International Nautical Mile. We also have information about recent international metric advances in countries still in the process of going metric.
For example, officially, the US has been metric since , , , or , depending on which official declaration you prefer to cite, and similar uncertainties apply to other countries. Last updated: We've moved to usma. Please update your bookmarks to reflect this change; the old domain name may stop working in the future. Your browser language doesn't seem to match your location.
It looks like you're visiting from , but your browser language is set to. Following are answers to miscellaneous questions about the metric system. How can I get a copy of the SI standard? Where can I get a list of SI prefixes and their origins? Where can I find unit conversion factors or calculators? How do you capitalize, abbreviate, and pluralize unit names and symbols? Is the symbol for the litre L or l? Is the litre the same as a cubic decimetre?
Is a micron the same as a micrometre? How big is a hectare? What about angles? Radians, steradians, degrees, … What about atmospheric pressure: hectopascals, kilopascals? Why does the base unit for mass, the kilogram, have a numeric prefix?
Should there be a space between the number and a unit symbol? How about commas to separate groups of three digits? What about the decimal point? How about billions and billions? How do you handle fractions of a metric unit? How about mixing units? Is it OK to use centimetres? How about multiple prefixes? How do you write units derived by multiplication or division?
Does an exponent apply to the prefix as well as the unit? Terminology The SI is a coherent system of units, but what does that mean? A metric century? A metric marathon? What about metric paper sizes? What about dates and times? Does the non-metric US system of measurements have a name? The liter is not the SI unit of volume Volume is a unit derived from length. Outside the United States, the word "meter" is spelled " metre " and the word "liter" is spelled " litre.
Metric Prefixes To change the scale of the base units, prefixes are attached. In addition to the base metric units, many other scientific quantities also employ this system of prefixes:.
0コメント