Essentially, an arc is sustainable and a spark is not. A spark is the onset of an arc. Whether it becomes sustainable or not, has to do with the supply of charges and electric field potential.
An arc, once formed, becomes very low in resistance and impedance akin to a metal conductor. The forming process of an arc includes a transition phase where in the formative phase, the dendrite type corona discharges begin to colapse into a single channel due to the collective magnetic fields. This self-induced magnetic field is large enough to contain it from expanding radially. Hans Mellberg Engineering Manager BACL 230 Commercial Street Sunnyvale CA 94085 USA 408-732-9162 x38 408-732-9164 fax ----- Original Message ----- From: "Speakman, Jim" <jim.speak...@uk.thalesgroup.com> To: <emc-p...@majordomo.ieee.org> Sent: Monday, September 22, 2003 8:32 AM Subject: Arcing & Sparking > > Fellow Listers > > At a recent equipment design review, a discussion on arcing and sparking > indicated a lack of definitive knowledge of the difference between an 'arc' > and a 'spark'. > > Is an 'arc', basically just a long 'spark'. If so, at what point > (precisely) does a 'spark' become an 'arc'? > > Have I got it all wrong? Are they 'something else'. > > Can anyone enlighten my darkness? > > __________________________ > Jim Speakman > (Design Safety Representative (Southern Sites) > > Thales Defence Ltd > Thales Sensors > Manor Royal > Crawley > West Sussex > RH10 9PZ > > > > * Tel: +44(0)1293 644911 > > * Mob: +44(0)7968 529439 > > * Fax : +44(0)1293 644194 > > * e-mail jim.speak...@uk.thalesgroup.com > > > __________________________ > This e-mail contains confidential information for the addressee only. If a > transmission error has misdirected this e-mail, please notify us on > +44(0)1293 644911 and delete it and all copies from your system. You should > not use, disclose, distribute or copy this communication if received in > error. > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: emc_p...@symbol.com > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > Archive is being moved, we will announce when it is back on-line. > All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
