Tolerance in text?

[Geoff Hart <ghart -at- videotron -dot- ca>]

Diederik Links wonders: <<What is the best way to write a measure with 
tolerance - where both '+' and '-' are equal - in a text (or 
non-technical illustration)? I normally write: "Drill a hole with a 
diameter of 25 +/-0.2 mm." "Drill a hole with a diameter of 25 ±0.2 
mm.">>

If I'm seeing the symbols correctly, there's nothing wrong with either 
approach; in fact, they seem to be identical on my computer, possibly 
because of a font encoding problem. (You're using a Dutch system, 
right?) You noted that:

<<Because the '±'-sign means 'approximately' (the hole can be 24 mm or 
26 mm) and not 'plus or minus' (the hole must be between 24.8 mm and 
25.2 mm).>>

I see the "plus or minus" sign on my computer, which does not mean 
approximately: it means that you should add or subtract the tolerance 
from the specified number.

If you mean approximately, it requires a different symbol than the one 
you typed. If I'm understanding this correctly, and your readers 
understand the concept of tolerance, this could be expressed most 
clearly as "a 25-mm-diameter hole (with a tolerance of 0.2 mm)". That 
means that the ideal hole is 25 mm in diameter, but that it could be 
0.2 mm wider or narrower without causing any problems.

If that's correct, then "approximately" would be incorrect, and 
potentially dangerously so. If the hole must be 25 mm, then the hole 
cannot be 24 or 26 mm, since that would be a 1-mm tolerance.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --
Geoff Hart   ghart -at- videotron -dot- ca
(try geoffhart -at- mac -dot- com if you don't get a reply)
www.geoff-hart.com
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

WebWorks ePublisher Pro for Word features support for every major Help
format plus PDF, HTML and more. Flexible, precise, and efficient content
delivery. Try it today!. http://www.webworks.com/techwr-l

Doc-To-Help includes a one-click RoboHelp project converter. It's that easy.  Watch the demo at http://www.componentone.com/TECHWRL/DocToHelp2005

---
You are currently subscribed to TECHWR-L as archive -at- infoinfocus -dot- com -dot- 

To unsubscribe send a blank email to
techwr-l-unsubscribe -at- lists -dot- techwr-l -dot- com
or visit http://lists.techwr-l.com/mailman/options/techwr-l/archive%40infoinfocus.com

To subscribe, send a blank email to techwr-l-join -at- lists -dot- techwr-l -dot- com

Send administrative questions to lisa -at- techwr-l -dot- com -dot-  Visit
http://www.techwr-l.com/techwhirl/ for more resources and info.