Abbreviations, Letter Symbols and Acronyms 4

The IEEE has a dictionary and a style guide. That is a good starting point for abbreviations, capitalization, etc.

Check their website for ordering information.

IEEE Std 280-1985(R1997) Standard Letter Symbols...

IEEE Style Manual

I don't mean to beat this subject to death, but using any of the preceding publications, how would you abbreviate 50 amperes of alternating current?
Have tried the two referenced web sites and also ANSI/IEEE Std 260-1978 (Reaffirmed 1985) IEEE Standard Symbols for Units of Measurement.
Should IEEE Std 280 be obtained?

Here's an opinion;

50 AMP AC

50 Amp AC

I think Ampier is capitalized because it is a person's name. Alternating current (AC) is in capitals because it is alternating current in the absolute sense (as compaired to "ac", incremental around an operating point).

Or 50 AAC, as a suggestion.

Actually, per IEEE Style Guide, abbreviation for Ampere would be capitalized since it is based on a proper name, but ac is not capitalized. So I would write:

50 A ac

This is consistent with IEEE journals and magazines.

Also, by convention (as opposed to edict) we tend to not put a space between 50 and A so it would be 50A, although I'm not sure about lower case ac. When purchasing transformers for instance, they are usually listed together with Volts in caps, as in 120VAC, not 120Vac. IMHO, Vac could be confused with the abbreviation for vacuum (although I admit it would probably be out of context).

Volts, like Amperes on the other hand are proper names and clearly always captialized , even when mixed in with mili-, as in 4-20mA.

To add to the controversy though (laughable as it is), why then do we mostly see DC capitalized, as in 50VDC? I rarely see it as 50V dc.

"Venditori de oleum-vipera non vigere excordis populi"

jraef,

I've gone back and forth on space between the numbers and the units (sometimes in the same sentence!). But IEEE publications seem to be quite consistent about always having the space. "dc" is definitely NOT capitalized per IEEE convention, but you do see it both ways.

And my last question: Does anal-retentive have a hyphen?

Let me try.

Names used as names are capitalized. Names used as units, in general, are not.

50 amperes ac, 60 hertz

Names used as units and abbreviated to other than their one or two letter symbol are lower case.

50 amps ac

The first letter of symbols of units based on names are capitalized.

50 A ac, 60 Hz

The last is preferred. It avoids the whole question of whether more than one of a unit is plural or not. (Hang on)

AAC, by the way, is not a unit. It's short for all aluminum conductor.

Per NIST's SI style guide, the only unit whose name is capitalized is the degree Celsius. All others, such as ampere and kelvin are lower case:


TTFN

And of course there is a similar style guide in the IEC world, and I wouldn't be at all surprised to discover it is not quite the same as the North American way!


Bung
Life is non-linear...