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World Metrology Day Poster

World Metrology Day is an activity of the International Bureau of Weights and Measures, of which the United States is a member. NIST is the U.S. national metrological institute, and NIST's Physical Measurement Laboratory (PML) sets the definitive U.S. standards for nearly every kind of measurement employed in commerce, government operations, and research -- sometimes across more than 20 orders of magnitude.

PML develops and disseminates the national standards of length, mass, force and shock, acceleration, time and frequency, electricity, temperature, humidity, pressure and vacuum, liquid and gas flow, and electromagnetic, optical, microwave, acoustic, ultrasonic, and ionizing radiation. Its activities range from fundamental measurement research through provision of measurement services, standards, and data.



We provide the science and services that make accurate measurements possible in nearly every aspect of daily life.


clock faceTIME   NIST develops and operates the atomic clocks that
set the official U.S. time, and distributes time information
by radio, Internet, and other methods.

meter ruleDIMENSIONS   NIST supports precision measurements
and calibrations ranging from a fraction of a nanometer
to tens of kilometers.

weight scaleWEIGHT   The Office of Weights and Measures helps
ensure the reliability of many different devices used in
commerce, from grocers' scales to gasoline pumps.

block and tackleMASS/FORCE   NIST measures masses as small as a few
millionths of a gram, and measures forces from tens of
piconewtons to a million pounds.

x-ray of handRADIATION   NIST maintains and disseminates the
standards or safe use of ionizing radiation in medicine,
industry, and homeland security.

hand with thermometerTEMPERATURE   The nation relies on NIST research and protocols for temperature control of processes from petroleum management to vaccine storage.

cell phone towerCOMMUNICATIONS   NIST standards and calibrations
improve the reliability of signal transmission and the
quality of microelectronic components.