Hi All, Did you know that a common accessory for FET probes can, in some cases, cause a significant error in the measurement? My September Technical Tidbit at:
http://www.dsmith.org describes the problem. The accessory in question is a probe tip with a small ground "spring" or "pin" on a hinge and uses a small ferrite core to improve probe response. Its use can make the FET probe ten times more sensitive to logic noise on the board and other EMI that you are not trying to measure. Such a sensitivity can cause one to "see" a glitch that is not there on a logic signal, a real time burner in the development lab or troubleshooting environment. The article presents scope data to show the magnitude of the problem which affects several brands of FET probes. The Technical Tidbit area is at the bottom of the index page. ---------- In addition, I have posted pictures to the website from Montreal and the IEEE EMC Symposium that was held there a few weeks ago. The link to the pictures is just above the Technical Tidbit area at the bottom of the index page. Doug -- ------------------------------------------------------- ___ _ Doug Smith \ / ) P.O. Box 1457 ========= Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-----( ) | o | Email: d...@dsmith.org \ _ / ] \ _ / Website: http://www.dsmith.org ------------------------------------------------------- ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
