Search results
Results from the WOW.Com Content Network
A cun (Chinese: 寸 ts'wun; Pinyin cùn IPA |mi=), often glossed as the Chinese inch, is a traditional Chinese unit of length.Its traditional measure is the width of a person's thumb at the knuckle, whereas the width of the two forefingers denotes 1.5 cun and the width of four fingers (except the thumb) side-by-side is 3 cuns. [1]
If using the metric unit meters for distance and the imperial unit inches for target size, one has to multiply by a factor of 25.4, since one inch is defined as 25.4 millimeters. distance in meters = target in inches angle in mrad × 25.4 {\displaystyle {\text{distance in meters}}={\frac {\text{target in inches}}{\text{angle in mrad}}}\times 25.4}
Conversions between units in the metric system are defined by their prefixes (for example, 1 kilogram = 1000 grams, 1 milligram = 0.001 grams) and are thus not listed in this article. Exceptions are made if the unit is commonly known by another name (for example, 1 micron = 10 −6 metre).
By default, the output value is rounded to adjust its precision to match that of the input. An input such as 1234 is interpreted as 1234 ± 0.5, while 1200 is interpreted as 1200 ± 50, and the output value is displayed accordingly, taking into account the scale factor used in the conversion.
The millimetre (SI symbol: mm) is a unit of length in the metric system equal to 10 −3 metres ( 1 / 1 000 m = 0.001 m). To help compare different orders of magnitude , this section lists lengths between 10 −3 m and 10 −2 m (1 mm and 1 cm).
Originally in 1945, the divisions were based on the ring inside diameter in steps of 1 ⁄ 64 inch (0.40 mm). [6] However, in 1987 BSI updated the standard to the metric system so that one alphabetical size division equals 1.25 mm of circumferential length. For a baseline, ring size C has a circumference of 40 mm. [7]
The U.S. government passed the Metric Conversion Act of 1975, which made the metric system "the preferred system of weights and measures for U.S. trade and commerce". The legislation states that the federal government has a responsibility to assist industry as it voluntarily converts to the metric system, i.e., metrification. This is most ...
The United States adopted the conversion factor 1 metre = 39.37 inches by an act in 1866. [30] In 1893, Mendenhall ordered the physical realization of the inch to be based on the international prototype metres numbers 21 and 27, which had been received from the CGPM, together with the previously adopted conversion factor. [31]