In response to Nancy Diehl questions on operating The Ionograph 500 and the response from the EMPF staff...... I have read and agree with Tim Crawford's explanation on how to run a dynamic bulk ionic contamination tester. If you do not have Tim's report published by the EMPF on how these puppies really work and what the results really mean, please contact the EMPF @ http://www.empf.org where you can order the document on-line. I forget the actual title, but the publication number is something like RD-0013. Good Luck, Steve Mikell, Process Engineer, Soldering & Cleaning SCI Systems, Government Division, Plant 13 [log in to unmask] Steve Mikell, Process Engineer, Soldering & cleaning processes SCI Systems Plant 13 [log in to unmask]