Daan, In a note to section 8.3.6 in I-STD-001C, it is written that "In comparing the sensitivity between methods, the solvent used to extract the residue, the method used to present the solvent to the assembly and the method of detecting the residue should all be considered. " I interpret that as you are allowed to and should do the correction. But if you use correction values, the figures given in the MIL standard are only valid for the models of cleanliness equipment that were used at that time. I guess Alpha Ionograph 500M is a later model, which means that it should have a different correction figure (probably higher since it likely has better cleaning efficiency). However, the use of equivalence factors has no scientific base. But on the other hand, neither has the method for cleanliness measurement. It shouldn´t be used as proof of the cleanliness of an assembly since it is no proof of assembly reliability. It is a good tool for process control, i.e. to control that the cleanliness of assemblies manufactured in certain line does not change with time. In my opinion, its use should be limited to that. Regards Per-Erik -----Ursprungligt meddelande----- Från: d. terstegge [mailto:[log in to unmask]] Skickat: den 30 september 2002 15:03 Till: [log in to unmask] Ämne: Re: [TN] Ionograph measurements Thanks Ron, I'll have a look at these standards. Unfortunately so far nobody could give me the evidence that I'm allowed to use an "equivalence factor" when measuring ionic contamination. The document that Per-Erik referred to comes very close (it mentions how the "A" version of the Ansi J-std-001 had an appendix with a statement about the equivalence factor), and I'm still expecting a report from Graham. Best regards, Daan >>> [log in to unmask] 09/30/02 01:06pm >>> Daan, the info is shown in table VIII in MIL-P-28809. It probably is also in MIL-C-28809, but I cannot find my copy of "C" to verify that. Ron Dieselberg CMC ELECTRONICS CINCINNATI [log in to unmask] -----Original Message----- From: Graham Naisbitt [mailto:[log in to unmask]] Sent: Friday, September 27, 2002 11:54 AM To: [log in to unmask] Subject: Re: [TN] Ionograph measurements > Hi Technet, > > One of our customers is complaining that the upper limit for our > ionograph test is set at 3.1 micrograms/cm2 instead of the 1.56 > micrograms/cm2 that the IPC/EIA J-STD-001C prescribes is section 8.3.6. > > I know there exists a document (probably an IPC or MIL-spec) > explaining how the 1.56 limit should be corrected for the exact type of > machine. For the Alpha Ionograph 500M the conversion factor is 2, > resulting in the 3.1 micrograms/cm2 limit. > However I can't remember where exactly this information can be found, > and I don't even know if it's still valid. Does anyone has a clue for me > ? > > Daan Terstegge > Unclassified mail > Personal Website: http://www.smtinfo.net > > ---------------------------------------------------------------------------- -- > --- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8e > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/html/forum.htm for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > ---------------------------------------------------------------------------- -- > --- > Daan I have a copy that I shall dig out for you. If anyone else needs a copy let me know -- Regards, Graham Naisbitt [log in to unmask] Mobile: +44 (0)79 6858 2121 Concoat Limited - Engineering Electronics Reliability Web: www.concoat.co.uk AND www.concoatsystems.com NOTE: NEW ADDRESS :NOTE Sales: Millfield House, Fleet Road Fleet, Hampshire GU51 3QF UK Phone: +44 (0)1252 813706 Fax: +44 (0)1252 813709 Manufacturing and Head Office: Alasan House, Albany Park Camberley, Surrey GU16 7PH UK Phone: +44 (0)1276 691100 Fax: +44 (0)1276 691227 ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------