Millimeter
Get Millimeter essential facts below. View Videos or join the Millimeter discussion. Add Millimeter to your Like2do.com topic list for future reference or share this resource on social media.
Millimeter
Millimetre
Ruler with millimeter and centimeter marks.png
Ruler with millimetre and centimetre marks
Unit information
Unit system SI derived unit
Unit of Length
Symbol mm 
Named after The metric prefix mille (Latin for "one thousand") and the metre
Unit conversions
micrometres = 1000 ?m
centimetres cm = 0.1 cm
metres m = 0.001 m
kilometres
inches 0.039370 in
feet 0.0032808 ft

The millimetre (International spelling as used by the International Bureau of Weights and Measures; SI unit symbol mm) or millimeter (American spelling) is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre.

One millimetre is equal to micrometres or nanometres. A millimetre is equal to exactly ​ (approximately 0.039370) of an inch.

Definition

Since 1983, the metre has been defined as "the length of the path travelled by light in vacuum during a time interval of of a second".[1] A millimetre, of a metre, is therefore the distance travelled by light in of a second.

Informal Terminology

A common shortening of millimetre in spoken English is "mil". This can cause confusion since in the United States, "mil" traditionally means a thousandth of an inch.

Unicode symbols

For the purposes of compatibility with Chinese, Japanese and Korean (CJK) characters, Unicode has symbols for:

  • millimetre (mm) - code U+339C[2]
  • square millimetre (mm^2) - code U+339F[2]
  • cubic millimetre (mm^3) - code U+33A3[2]

In Japanese typography, these square symbols were historically used for laying out unit symbols without distorting the grid layout of text characters.

Measurement

On a metric ruler, the smallest measurements are normally millimetres.[3] High-quality engineering rules may be graduated in increments of 0.5 mm. Digital callipers are commonly capable of reading increments as small as 0.01 mm.[4]

Microwaves with a frequency of 300 GHz have a wavelength of 1 mm. Using wavelengths between 30 GHz and 300 GHz for data transmission, in contrast to the 300 MHz to 3 GHz normally used in mobile devices, has the potential to allow data transfer rates of 10 gigabits per second.[5]

The smallest distances the human eye can resolve is around 0.02 to 0.04 mm, approximately the width of a human hair.[6] A sheet of paper is typically between 0.07 mm and 0.18 mm thick, with ordinary printer paper or copy paper approximately a tenth of a millimetre thick.[7]

See also

References

  1. ^ "17th General Conference on Weights and Measures (1983), Resolution 1". International Bureau of Weights and Measures. Retrieved 2013.
  2. ^ a b c "CJK Compatibility" (PDF). unicode.org. Retrieved 2013.
  3. ^ "How do I read a ruler?". onlineconversion.com. Retrieved 2013.
  4. ^ "Accuracy of Calipers". TresnaInstrument.com. Retrieved 2013.
  5. ^ Huang, Kao-Cheng; Wang, Zhaocheng (2011). Millimeter Wave Communication Systems. ISBN 9781118102756.
  6. ^ "How Small Can the Naked Eye See?". Focus Magazine. Retrieved 2013.
  7. ^ "Thickness of a Piece of Paper". hypertextbook.com. Retrieved 2013.

  This article uses material from the Wikipedia page available here. It is released under the Creative Commons Attribution-Share-Alike License 3.0.

Millimeter
 



 

Top US Cities

Like2do.com was developed using defaultLogic.com's knowledge management platform. It allows users to manage learning and research. Visit defaultLogic's other partner sites below:
PopFlock.com : Music Genres | Musicians | Musical Instruments | Music Industry