Normally, you do test the entire panel when doing ionic cleanliness testing. You calculate the surface square feet of the panel (in case of an 18" X 24" panel, that would be 6.00 square feet) and then add the volume of solution (usually a 75%/25% blend of isopropyl alcohol/DI water) to just cover the panel in the tank. Depending on the particular machine, you either input the specifics of the test (square footage of panel, volume of solution, etc) into the processor or you do it by hand calculator. You can cut up the panels to do the test; however, I would recommend that you get an instrument that will accommodate your largest panels (don't think there is too much difference in cost). In this manner, you have a totally non destructive test and the test results will be totally representative of the panel, not just a portion of it. Hope this helps Larrry Fisher Dexter Electronic Materials [log in to unmask] ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################