They should be the same, as Blair said. Sounds like the soldering iron and mat are not connected to the same "ground". This is not an ESD issue, rather an EOS issue and yes it could be very damaging. When the electrical system ground is open I have measured potentials between 40 and 90 volts. That is where I would look first. What is the resistance to ground through the iron? Do you have a GFI on the solder iron? Check for a faulty ground at the outlet. Then check the AC box. How old is the building? > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Karnwal, Pankaj > Sent: Tuesday, February 10, 2004 4:26 AM > To: [log in to unmask] > Subject: [TN] iron tip potential > > > Dear all, hello > > My question about the potential deference between the > soldering iron tip and the ESD grounded mat. I observed that > it is about 20 to 30 volts, is it safe for ESD sensitive > device? and is it mandatory to keep the iron tip on same > potential with ESD grounded mat. > > > > Pankaj Karnwal > Jr. Engineer QA > > Barco Electronics System (P) Ltd. > WWW.barco.com mailto:[log in to unmask] --------------------------------------------------- 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 -----------------------------------------------------