Re: Use of term nominal and nominally

[Tim Altom <taltom -at- SIMPLYWRITTEN -dot- COM>]

>Can anyone expand on the engineering use of the term "nominal" and its
>adverbial alternative "nominally"?  (As in "nominally -48 VDC) What
>synonyms are commonly used for this sense?
>
Nominal means "in name, at least". It's come to be an unfortunate synonym
for "approximately", but that's not quite the same thing.

An American piece of lumber is common called a "two-by-four" because it was
once two inches by 4 inches in cross-section. No more. Yet, it's a nominal
two-by-four without being approximately two inches by four inches. It's a
two-by-four in name only.

The use of "nominal" in such constructions as "nominally 48 volts" is
borderline at best. In that construction it's synonymous for "using 48 volts
as a target with a band of acceptable variation plus and minus". In that
case I'd rather use "48 volts, plus or minus 5 volts." It's more precise and
avoids the sloppy use of "nominal".

If I had my way I'd save "nominal" for usages that truly are names of items:
.38 Special, for example. I'd prefer to see "approximately" or "approximate"
where appropriate: approximately 8 inches deep. And in cases where the
meaning is "such-and-so, plus or minus", I'd say so.

Tim Altom
Simply Written, Inc.
317.899.5882
http://www.simplywritten.com
Creators of the Clustar Method for task-based documentation