I have a project that seems to be a good candidate for a current sense resistor made as a part of the PCB. I am using the free calculator, PCBTEMP, from the UltraCAD website (http://www.ultracad.com/calc.htm) for geometry calculations. I need to know the expected variability in thickness, batch to batch, for the copper foil on 2-oz stock. I can live with the 0.4% TC of the Cu, but I need to evaluate all the other variables in my error budget before I present my proposal. I would appreciate any success (or horror) stories from people who have (not) used the board copper as a current sense method. Thanks, Carl Carl Van Wormer Cipher Systems 1815 NW 169th Place, Suite 5010 Beaverton, OR 97006 Phone (503)-617-7447 Fax (503)-617-6550 --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------