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Metric News

Metric Week 2014: Introducing the League of SI Superheroes - The New Champions of Metric

October 2014

To celebrate Metric Week (Oct. 5-11), the National Institute of Standards and Technology would like to introduce you to the League of SI Superheroes. The League of SI Superheroes use their incredible powers of measurement to perform amazing feats of science and engineering. Measurement is an incredibly powerful tool. Measurements are how we describe what we know, uncover what we don't know, ensure quality and enable creativity. Rear Admiral and computing pioneer Grace Hopper famously said, "One accurate measurement is worth a thousand expert opinions." What she meant is that opinions are fine, and expert opinions are even better, but they aren't knowledge until there are measurements to back them up.

The customary units in the United States grew out of our everyday experience. Gallons, feet and pounds were conveniences based on prescientific notions of accuracy and repeatability that served, and continue to serve, people's everyday needs adequately enough (though their continued use does act as a barrier to trade and can occasionally lead to mishaps). Read More.

July is National Ice Cream Month

July 2014

Cool down this summer with a classic frozen dessert and celebrate National Ice Cream Month! Americans are not alone in enjoying a delicious serving of ice cream, consuming about 14 L per capita annually. Not surprisingly, the International Dairy Foods Association (IDFA) reports that about 9 percent of all the milk produced by U.S. dairy farmers is used to produce ice cream.

It's estimated that about 98 percent of American households purchase ice cream! No wonder that President Ronald Reagan designated July as National Ice Cream Month and the third Sunday of the month as National Ice Cream Day. This year, National Ice Cream Day will be Sunday, July 20, 2014. Read more.

Introducing the League of SI Superheroes

June 2014

League of SI Superheroes cover
Enjoy a new comic book-style video animation featuring the "League of SI Superheroes", which is available on the NIST YouTube Channel. The NIST Public Affairs Office (PAO) developed the video to help middle school students learn about the 7 base measurement units. In their first adventure, Desperate Measures, the SI Superheroes use the power of measurement to help a stranded soccer player get home! The cast of characters include: Mole, Professor Second, Monsieur Kilogram, Mizz Ampere, Dr. Kelvin, Meter Man, and Candela. Be sure to add your comments on the NIST YouTube Channel and let us know what you think.

Welcome to the Minecraft Measurement Units Video Challenge!

April 2014

The NIST Public and Business Affairs Office has announced the Minecraft Measurement Units Video Challenge. Your Challenge (should you choose to accept it) is to create one or more video clips in Minecraft that teaches others about what the seven units of the International System of Measurement (SI) are or why they are important in a fun way. Participants should post a link to your completed videos in the comments on YouTube.


  • The total running length of each clip should be no longer than 20 seconds.
  • Only one SI unit should be featured per clip.
  • Videos must be G-rated.
  • Do your own work, please.

The seven base SI units are:

  1. Meter (m)—length, used for measuring the distance between things;
  2. Second (s)—time, there are 60 of them in a minute;
  3. Ampere (A)—an amount of electric current, quite shocking;
  4. Candela (cd)—brightness, the amount of useful light (light humans can see by) an object emits;
  5. Kelvin (K)—temperature, this unit tells you how hot or cold something is;
  6. Kilogram (kg)—mass, a measure of the amount of matter an object has, related to, but not the same as, weight; and
  7. Mole (mol)—an Avogadro's number's worth of "entities," like a chemist's, as opposed to a baker's, dozen (One mole of something has 6.022 x 1023 atoms or molecules.)

Good luck!

Read more.

Presidents and Measurements

February 2014

Presidents' Day is a national holiday celebrated on the third Monday in February and is as a day where all U.S. presidents are remembered and honored. Enjoy the holiday by exploring these measurement education resources.

  • In the Presidential Height Challenge students are encouraged to examine the height of ten U.S. presidents found in the data table. Graph each president's height (meters) in increasing order. Who was the tallest and the shortest? Where does your height fall in this arrangement? Check your solution using the graph provided.
  • Many Presidential Monuments have been established to remember presidential legacies and often include a monument, sculpture, or statue located on the site. Explore these amazing memorial measurements.
  • Throughout our country's history, Presidential and Congressional decisions have influenced all aspects of American life, including how measurements are used. Enjoy the Presidential Measurement Timeline chronology beginning with the leadership of our first president, George Washington.
    Read More.

SI Teacher Kits Available for Educators

January 2013

Attention Teachers! Did you know that you can obtain a free set of metric education resources for use in your classroom? Contact the NIST Metric Program at TheSI [at] (TheSI[at]nist[dot]gov) and include your name, school, subject, grade level, phone number, and mailing address. The NIST SI Teacher Kit a classroom set of metric rulers (NIST SP 376 - a 300 mm ruler), laminated metric conversion cards (NIST SP 365), SI Education CD, and other measurement resources. Read More.

Metric Week Begins October 9!

October, 2011

Counting the seconds until Metric Week (Oct. 9-15, 2011) begins? That's the spirit! Seconds are the metric unit of time. You also could figure your distance in meters (the metric unit of length) from the National Institute of Standards and Technology (NIST) labs in Gaithersburg, Md., where it's metric all year round. Read More.

'SI' on the New SI: NIST Backs Proposal for a Revamped System of Measurement Units

October, 2010

Taking the first steps of what would be a major historical advance in the science of measurement, the National Institute of Standards and Technology (NIST) is participating in a worldwide effort to recommend major revisions to the International System of Units (SI), the modern metric system that is the basis of global measurements in commerce, science and other aspects of everyday life. The new SI, which would be based on seven constants of nature, would enable researchers around the world to express the results of measurements at new levels of consistency and accuracy. Read More.

Metric Week Begins 10/10/10

October, 2010

Every day is a metric day at the National Institute of Standards and Technology (NIST). But that won't stop the agency from celebrating Metric Week, held annually the week of Oct. 10—the tenth day of the tenth month. Read More.

Proposed Rules Would Allow Metric Labeling for Some Products

June, 2010

The National Institute of Standards and Technology (NIST) has issued two publications calling for the amendment of labeling laws to allow the voluntary use of only metric units on some consumer products. NIST researchers hope that adoption of metric labeling will lead to greater agreement between state and federal labeling laws and simplify domestic and international commerce. Read More.

How Deep are Earth's Oceans?

May, 2010

Using satellite measurements, researchers from the National Oceanic and Atmospheric Administration (NOAA) National Environmental Satellite, Data and Information Service and Woods Hole Oceanographic Institution (WHOI), Department of Marine Chemistry and Geochemistry, have come with up with a new ocean volume figure. The study's calculation of the ocean's mean depth is 3,682.2 meters, which is 21 - 51 meters less than previous estimates. Read More.

Celebration of World Metrology Day

May, 2010

NIST will hold its fourth annual celebration of World Metrology Day on Thursday, May 20, 2010. The Metre Convention was signed on 20 May 1875, a date now celebrated as World Metrology Day. The Convention created the International Bureau of Weights and Measures (BIPM) and set the framework for global collaboration in the science of measurement and in its industrial, commercial and societal application. The original aim of the Metre Convention – the worldwide uniformity of measurement – remains as important today, in 2010, as it was in 1875. Read More.

SI Educational Opportunity at NIST

April, 2010

On Friday, April 16, 2010, 10:30 am, Terry Quinn, Director Emeritus, BIPM will present "The Metre, The Kilogram and the Creation of the BIPM" during the NIST Colloquium Series. The event will be held at the NIST Administration building, Green Auditorium. Anyone outside NIST wishing to attend must be sponsored by a NIST employee and receive a visitor badge. Read More.

EU Metric-Only Labeling Directive Revised

May, 2009

The EU Metric Directive (80/181/EEC), scheduled to go into effect January 1, 2010, has been modified to allow the continuation of both supplemental (U.S. customary, inch-pound) and metric units for consumer goods sold in the EU. The rule was published on May 7, 2009 in the Official Journal of the European Union PDF.

The Directive instructs the European Commission to produce a report to the Parliament and Council regarding the smooth functioning of the internal market and international acceptance of SI units by December 31, 2019, including proposals where appropriate.

Demonstrated progress will be important for U.S. stakeholders to achieve long-term acceptance of supplemental units in the EU. Modifying the U.S. Fair Package and Labeling Act (FPLA), which currently requires dual labeling, to permit optional metric labeling is an example where greater international marketplace acceptance of SI units can be achieved.

NIST Metrology Day Celebrates Measurements in the Market

April, 2009

The next time you shop for frozen seafood, and the price per pound seems enticingly low, make sure that you are really getting a full 16 ounces of fish. Unethical merchants or suppliers may try to have you pay fish prices for ice by including the weight of the ice, not just the weight of the fish. The National Institute of Standards and Technology (NIST) will celebrate World Metrology Day on May 20 by holding a symposium in Gaithersburg, Md. The symposium on "Measurements in Commerce: Metrology Underpinning Economic Development" will emphasize how measurement science and standards play an everyday role in our global economy.

Lisa Weddig, the director of regulatory and technical affairs at the National Fisheries Institute (NFI) in McLean, Va., will describe international trade and the importance of accurate measurements for seafood products, which represent billions of pounds of commerce every year. Fair competition between seafood suppliers only becomes possible when all sellers declare the proper weight on seafood products and avoid deceptive practices such as substituting a cheaper species of fish for the one listed on the label. NFI members have established the Better Seafood Board to ensure that fair trade exists with proper declarations on seafood products. Read More.

SI (Metric) Measurements Help U.S. Healthcare Industry Increase Patient Safety

April, 2008

In April 2008 the Joint Commission, formerly the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), an independent, not-for-profit healthcare organization accreditation and certification body, issued a Sentinel Alert PDF to accredited organizations that all pediatric patients should be weighted in kilograms (kg) at the time of admission, including outpatient and ambulatory clinics, or within 4 hours of admission in an emergency situation. The Joint Commission states that kilograms should be the standard nomenclature for weight on prescriptions, medical records, and staff communications. Medication errors are believed to be the most common type of medical error and are a significant cause of preventable adverse events.

U.S. healthcare institutions, such as the Monroe Carell Jr. Children's Hospital at Vanderbilt PDF, Nashville, Tennessee and the Austin Medical Center, Mayo Health System PDF, Austin, Minnesota, are increasingly switching to exclusive SI measurements for patient care to lower the potential for patient safety errors and increase quality patient care. Examples include modifying scales to measure in only grams and kilograms, using Celsius thermometers instead of Fahrenheit, measuring length in terms of meters, and maintaining metric record and documentation systems. Hospitals are working to education patients in areas such as the newborn nurseries and emergency rooms, where customary (inch-pound) units have historically been used.

Hydrogen Energy to Expand Use of the SI

April, 2008

New technologies present opportunities for increasing the use of the SI (metric system). For example, the U.S. National Work Group for the Development of Commercial Hydrogen Measurement Standards - Fuel Specification Sub-committee has proposed Hydrogen Fuel Method of Sale based on basis of the kilogram (kg) and the pascal (Pa) in commercial sales and on street signs. If implemented, the U.S. approach would be consistent with the global hydrogen marketplace in terms of the method of sale. Learn More.

NIST Offers U.S. Interpretations of Recent SI (Metric) Changes

March, 2008

NIST has issued a new American version of the English language SI Brochure, the eight edition of the international standard reference guide to the metric system. The SI plays an essential role in trade and commerce and is the common language of scientific and technological research and development.

The 2008 edition of NIST Special Publications (SP) 330, the International System of Units (SI), cover correct U.S. usage of metric units. In another update, NIST SP 811, Guide for the Use of the International System of Units (SI), complements SP 330, and is published to assist NIST authors and others in correct SI usage and unit conversion. An extensive conversion factor appendix offers help in measurement unit conversions and in appropriate rounding-off of data. SP 811 also provides an editorial checklist for reviewing manuscripts' conformity with the SI and the basic principles of physical quantities and units. A color diagram has been added that illustrates the utilization of the SI base units in defining the 22 derived units with special names and symbols. Read More and Download Documents.



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Created January 13, 2010, Updated November 17, 2017