Path: utzoo!attcan!uunet!ginosko!xanth!ames!oliveb!pyramid!prls!mips!vaso
From: vaso@mips.COM (Vaso Bovan)
Newsgroups: sci.electronics
Subject: Rational Capacitor Prefixes
Keywords: nF, cap value prefixes
Message-ID: <26043@quacky.mips.COM>
Date: 23 Aug 89 04:30:53 GMT
Reply-To: vaso@mips.COM (Vaso Bovan)
Followup-To: sci.electronics
Organization: MIPS Computer Systems, Sunnyvale, CA
Lines: 19

This is a plea to rationalize capacitor unit suffixes. Most postings
give capacitances in terms of pF or uF. Unfortunately, this often means
capacitances are are stated in inconvenient units. ie caps with the following
units are given 4700pF ; .0047uF ; .001uF !  It is a nuisance to have to count
the decimal places, but there is at least one situation where the "dot"
placement can actually cause mistakes: In photocopying schematics, "dots" are
added and taken away at random. 0.01uF might easily be mistaken for .001uF.

In conformance with good S.I. practice, the "nanofarad" is coming into wide
usage. (European schematics have long used nanofarads). eg .01uF becomes
10nF. 4700pF becomes 4.7nF. The ubiquitous .1uF (or 0.1uF) becomes 100nF. The
use of dot decimal places is not eliminated, but is substantially reduced.
(Yes, I know, for the purist it should be 47 nF (ie with a space), but that
often looks peculiar in non-proportional pitch.

Those who balk at nanofarads should consider it wasn't long ago that 
"puffs" were given as uuF, eg 47uuF.

ps  Another barbarity is to use pf and uf instead of pF and uF...