Thanks Joe, I was looking at an older revision in the back of a J-STD-001 book - I should have checked the latest and greatest. My bad!!! Send Dewey over to whip me with a wet noodle - he seems to be fixated on pasta today. regards, - Graham -----Original Message----- From: Joe Russeau [mailto:[log in to unmask]] Sent: Tuesday, February 19, 2008 2:08 PM To: TechNet E-Mail Forum; Collins, Graham (FN) @ ESI Subject: Re: [TN] cleanliness testing Hi Graham, Take a look at the latest revision of IPC method 2.3.25 rev C. It describes how to make the conversions from resistivity to ug of Na/Cl equivalents / sq. inch under section 4.4. You will need your supplier to provide you with the calibration curve of the bridge probe they used on the day that the test in question was performed. In addition, you will need the volume of solution they used. Also, if you don't have this method you can find it for free at IPC's website. Go to Knowledge, then Standards, then TM-650 test methods download page, then section 2.3 chemical tests. I hope this helps. Best Regards, Joe Russeau Precision Analytical Laboratory, Inc. ----- Original Message ----- From: "Graham Collins" <[log in to unmask]> To: <[log in to unmask]> Sent: Tuesday, February 19, 2008 12:35 PM Subject: [TN] cleanliness testing Hello TechNet I'm in a debate with a supplier about the incoming cleanliness of one of their parts, they claim it's squeaky clean and I claim it's as salty as a bag of salt & vinegar potato chips. Obviously we are both exaggerating, but one of us has a good claim. They are fending me off with resistivity measurements made per the manual test method IPC-TM-650 2.3.25 - which works in that I don't know how to convert it to the "ug NaCl/in2" equivalent units I'm used to. Is there a valid conversion? Sir Doug of Dew, if you reply please do NOT say it depends... regards, Graham Collins Halifax Production Engineering L-3 communications Electronic Systems (902) 873-2000 ext. 6215 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------