[ARC5] SI Units - Careless Errors Abound

[J. Forster]

>> In Germany it was kHz and MHz ever since it was adopted.
>
> Which was in 1930.
>
> Other examples of careless unit errors are using:
>
>   hz vs. Hz        Unit *symbols* are capitalized when it represents a
> proper name.
>
>   Hertz vs. hertz  Units are NOT capitalized when spelled out (in English
> usage).
>
>   mHz vs. MHz      m in the SI system is 1/1000.
>                    M in the SI system is 1000000.
>                    mHz means millihertz.
>                    MHz means megahertz.
>                    (Using the wrong letter results in specifying
>                     a value incorrect by a factor of 1000000000!!!)
>
>   KHz vs. kHz      K in the SI system is Kelvin.
>                    k in the SI system is 1000.
>                    KHz means kelvin hertz (nonsense).
>                    kHz means kilohertz.
>
>   KV vs. kV        kelvin volts (nonsense) vs. kilovolts
>
> So...it's best to drop incorrect mhz or mHz or Mhz for the correct MHz,

mHz is correct for millihertz. It is used, and correctly.

>  and it's best to drop incorrect KHz or Khz or khz for the correct kHz.
>
> Another common error occurs when units are combined, such as battery
> capacity:
>
> A milliampere hour should be mA h, not mah or ma-h or mAhr or MAH or some
> other combo.
>
> Symbols should mean something.

Agreed.

I believe, to simplify things, when a quantity is named after a person, it
is correct to capitalize. When it's a multiplier, it is lower case.

The only exception I can think of offhand is M for mega.

-John

===========






>
> Mike / KK5F
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