True ESD shelving has a dissipative coating on it. Purely metal shelving can be construed to be ESD shelving, provided that the only product stored on it is in Faraday cages that will dissipate any charge to the shelving. Having unprotected ESD assemblies sitting directly on a metal shelf that is connected directly to ground does not constitute protection. Metal shelves without benefit of dissipative coating should be connected to ground through a 1 meg resistor. This prevents a direct charge from going through the assembly, whether from ground to a positively charged person or object, or vice-versa. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Dave Dixon Sent: Tuesday, November 18, 2008 11:10 AM To: [log in to unmask] Subject: [TN] ESD Shelving Question Hi Gurus, We just noticed that our supposed ESD shelving has a clear thin insulative coating on it. The grounding clamps bite into this coating, and if you poke a probe through the coating, you can see that the shelves are connected to ground. This runs against all my beliefs about shelving materials. Shouldn't they be conductive on the shelves' surface area as well? Thanks in advance for any input! Dave Dixon Engineering Technician Aero-Mach Labs Inc. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 -----------------------------------------------------