I don't know many of the details, but those levels came from the 801 series back in the early 80's. A gentleman named Reyser from Switzerland did many measurements, as did Pete Richman at KeyTek, a consultant whose name excapes me, and others. You would have to scan the literature from the EOS/ESD back in the early 80's to get the details.
I do remember reading a study that suggested 15kV to be the extreme because the people being charged to that level in the lab wouldn't go any higher! Other studies back then, and more recently confirmed by Pommerenke of HP, indicated faster risetimes at lower voltages, which explained failures I saw in demo's where products failed at 2-4kV but passed when tested at 10kV. To really understand the issues, one would have to do considerable research, but the real point is that the levels in IEC appear to be okay in terms of replicating reality -- failues in equipment can be demonstrated to correlate with field problems at low voltages; 15kV is probably at the extreme for most normal environments (automotive goes to 20-25kV and other industries have higher voltages). Hope this is helpful. Mike Hopkins [email protected] > -----Original Message----- > From: Bailin Ma [SMTP:[email protected]] > Sent: Thursday, May 07, 1998 3:59 PM > To: [email protected] > Subject: RE: fwd: ESD level measurement on equipment > > Darrell, > > Please allow me to try again phrasing my questions in detail. > When a committee was discussing and working out on an EMC standard they > usually first set up a reasonable model that MOST LIKELY represents the > EMC > situation concerned in the real life. Say, CISPR 22 Class B was based on a > > model that the radiated emission from the DUT should not interfere with > the > reception of an ordinary TV set located 10 meter apart. Then they figured > out 30/37 dBuV/m limits for Class B DUT. > Therefore, my questions are "What is the model that 8/4 kV of IEC > 1000-4-2 are based on?" and "How did they make the measurements on the > model and figure out the 8/4 kV specs?" > > Thanks. > Best Regards, > Barry Ma > ------------- > Original Text > From: "Darrell Locke (MSMail)" <[email protected]>, on 5/6/98 > 12:50 > PM: > Barry, > > Where does the standard IEC 1000-4-2 specify that 8kV and 4kV are the > most likely? I have the 1995 edition. > > Thanks > > Darrell Locke > Advanced Input Devices > ---------- > From: Bailin Ma > To: [email protected] > Subject: fwd: ESD level measurement on equipment > Date: Wednesday, May 06, 1998 8:25AM > > > A related question: > How come the IEC regulated that +/- 8kV air & +/- 4kV contact ESD in IEC > 1000-4-2 most likely represent ESD in the real life. They must have > been > based on many measurement data. > Barry Ma > ------------- > Original Text > From: "Campi, Mike" <[email protected]>, on 5/5/98 4:08 PM: > To: > > We manufacture laptops and docking stations. Our QA department has > discovered a problem that may be due to an ESD issue when we dock our > laptop into the docking station. Is there a way of measuring the > potential between these devices reliably? Is there equipment that can do > this? and where can we get this equipment? > > Someone mentioned that a charge plate monitor may be able to do the job. > Anybody have experience with this equipment? > > Thanks, > > Mike Campi > Corporate Compliance Engineer > Fujitsu PC Corp.
