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Message-ID: <3.0.6.32.20020226080539.00a6e670@pop.netspace.net.au>
Date: Tue, 26 Feb 2002 08:05:39 +1100
To: rsgb_lf_group@blacksheep.org
From: "Richard Rogers" <vk7ro@netspace.net.au>
Subject: RE: LF: Spelling of units
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References: <5.1.0.14.0.20020225161512.009ed5c0@POP3.freeler.nl> <20020225105439.1D8961E456@xprdmailfe.excite.com>
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I recall that the now defunct magazine "Electronics Australia" started to
delete the space between the figure and the unit to avoid problems with
their new-fangled computerised typesetting system which would sometime
leave the 5 on the end of one line and put the V at the beginning of the
next.   There appears to be an example of this problem in the message below.

At 05:18 PM 2/25/02 +0000, you wrote:
>Dear LF Group,
>
>A lot of the variations on symbols for units seem to be due to computers; 
>for instance, most CAD and simulation software can't do Greek letters and 
>is not case-sensitive. The Pspice simulator that I use at work a lot 
>interprets a resistor of either 1m or 1M as 1 milliohm - you have to put 
>1meg if you want a 1 megohm resistor. Confusingly, while 4.7k gives what 
>you would expect, it will interpret 4k7 as 4 kilohms, and ignore the 7. 
>Fortunately, 'u' is not used in many units, so uF has fairly obvious 
>meaning. Also, the word processor I use puts nasty red lines underneath 1 
>mA, but seems to approve of 1mA - perhaps it is American influence at 
>work!  I think the use of * to indicate multiplication stems from many 
>types of computer languages which use this notation to avoid the ambiguity 
>possible if 'x' or '.' were used instead in a text-only display.
>
>The standards bodies seem to have been determined that we should use the 
>new logic symbols for a couple of decades now - engineers around the world 
>seem equally determined not to use them! The resistor symbol is a bone of 
>contention too, with many still preferring the zig-zag line over the 
>rectangular box.
>
>Some old American books seem to use 'M' for ohms - so there are lots of 
>50,000M resistors marked on circuit diagrams, which looks a bit strange...
>
>Cheers, Jim Moritz
>73 de M0BMU
>
>
>
73, Ric, VK7RO