[ARC5] SI Units - Careless Errors Abound

[mac]

Ah yes, I shudder to recall how many fruitless hours I've spent trying  
to get a rig to perform properly on 3870 KHz when I should have been  
tuning to 3.870 MHz...  :^)

Dennis D.  W7QHO
Glendale, CA

*****************
On Jan 7, 2012, at 12:07 PM, Mike Morrow wrote:

>> 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,
> 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.
>
> Mike / KK5F
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