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From: vaso@mips.COM (Vaso Bovan)
Newsgroups: sci.electronics,rec.ham-radio,sci.astro,sci.space
Subject: Units of Measure (was fluxgate magnetometer)
Summary: Tower of Babel
Keywords: MKS cgs flames
Message-ID: <30329@buckaroo.mips.COM>
Date: 30 Oct 89 00:13:03 GMT
References: <1914@sactoh0.UUCP> <28601@buckaroo.mips.COM> <1989Oct29.174631.12960@ux1.cso.uiuc.edu>
Reply-To: vaso@mips.COM (Vaso Bovan)
Organization: MIPS Computer Systems, Sunnyvale, CA
Lines: 33

In article <1989Oct29.174631.12960@ux1.cso.uiuc.edu> mcdonald@aries.scs.uiuc.edu (Doug McDonald) writes:
>>>
>>>I would like to measure changes at least as small as
>>>10 gammas (.001 Gauss), and if possible, even smaller.
>>>
>>
>>?  You mean of course, nanotesla (nT), since 1954.  :-)
>
>I have been in the science business for over 20 years and have
>never heard anyone refer to magnetic fields in Tesla - everyone
>uses gauss. It is true that people know that someone somewhere
>created a unit of magnetic field called a Tesla, but no one
>remembers how many gauss are in one Tesla, and no one uses it.
>Sometimes it might appear in a textbook (usually directed at
>freshmen or sophmores - more advanced books use gauss).
>
>There are lots of names of units out there that are simply not used.
>

There are too many units out there that ARE being used. That is the reason
various international technical standardization organizations has strived
for a minimal set of clearly defined units. Unfortunately, there are many
authors who insist on dragging their feet on the changeover, so that one often
sees, for instance cgs and SI metric units intermingled, even within the same
equation !  I note that refereed journals usually require SI metric, but allow
obsolete cgs units "where traditional." This is an unfortunate loophole. I'm
an electrical engineer. I have to deal today with gauss, tesla, and microns,
all to describe the same parameter. (I won't even mention the profusion of
inch-based electro-magnetic units which are STILL found in new textbooks).

Let's not even start on the disgraceful reluctance of certain sectors of
U.S.A. engineering, mechanical engineers in particular, to expedite conversion 
to metric measure.