Changes between Version 6 and Version 7 of WikiStart


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Timestamp:
10/18/07 15:26:32 (17 years ago)
Author:
gschadow
Comment:

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  • WikiStart

    v6 v7  
    2525
    2626 1. ISO 2955 and ANSI X3.50 contain numerous name conflicts, both direct conflicts (e.g., "a" being used for both year and are) and conflicts that are generated through combination of unit symbols with prefixes (e.g., "cd" means candela and centi-day and "PEV" means peta-volt and pico-electronvolt.)
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    2827 1. Neither ISO 2955 nor ANSI X3.50 cover all units that are currently used in practice. There are many more units in use than what is allowed by the Systèeme International d'Unités (SI) and accompanying standards. For example, the older CGM-units dyne and erg are still used in the science of physiology. Although ANSI X3.50 extends ISO 2955 with some U.S. customary units, it is still not complete in this respect. For example it doesn't define the degree Fahrenheit.
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    3028 1. ANSI X3.50 is semantically ambiguous with respect to customary units, even if we do not consider the history and international aspects of customary units. Three systems of mass units are used in the U.S., avoirdupois used generally, apothecaries' used by pharmacists, and troy used in trade with Gold and other precious metals. ANSI X3.50 has no way to select any one of those specifically, which is bad in medicine, where both apothecaries' and avoirdupois weights are being used frequently.
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