The conventions regarding significant digits and rounding are widely misunderstood in our general industry, despite adequate coverage in undergraduate courses at colleges and universities.
This misnomers 'round-up' and 'round-down' are just two that bug me a little. Ralph McDiarmid, AScT Compliance Engineering Group Xantrex Technology Inc From: [email protected] [mailto:[email protected]] On Behalf Of John Woodgate Sent: Tuesday, March 31, 2009 10:55 PM To: [email protected] Subject: Re: [PSES] 10cm above GRP requirement for 61000-4-6 In message <[email protected]>, dated Wed, 1 Apr 2009, "ce-test, qualified testing bv - Gert Gremmen" <[email protected]> writes: >At school I learned: > >" When no tolerance is given, +/- half of the number of significant >digits is assumed. " > >When writing down 10 there is only one significant digit, so +/- 5 cm >will do. > >Note : 10. (10dot) has 2 significant digits > >http://en.wikibooks.org/wiki/FHSST_Physics_Units:Scientific_Notation,_S i > gnificant_Figures_and_Rounding That notation isn't used by IEC/CISPR, where the standard came from. Don't just discuss it, take it up with the TAG for IEC SC77B and get it changed. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Things can always get better. But that's not the only option. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
