Another point is that at lower voltages, the real rise times (the dv/dt) can be quite a bit higher --- especially below about 5kV....
Mike Hopkins KeyTek -----Original Message----- From: Cortland Richmond [mailto:72146....@compuserve.com] Sent: Wednesday, April 25, 2001 2:33 AM To: jrbar...@lexmark.com; ieee pstc list Subject: Re: ESD generators max Contact discharge level Lower voltages, because of less corona, tend to have more energy, sooner, relative to the total. You might pass a 15 kV air discharge test -- but fail, lower. We ALWAYS want margin, and others ALWAYS want none. My experience in a previous area of the industry is, this lasts until a rash of field failures costs someone a lot of money. The nature of the contact discharge test is such that the charge is not even applied to the electrode until it's in position, and then, humidity is not a factor. However, in a dryer atmosphere, you might experience more FIELD failures, since people using the equipment will be charging up to higher voltages. You have a good point, though; for the reason you mention, there is a limit on humidity for doing ESD testing, which I believe is 70 percent -- my references are at the office and I'm at home. Cortland ------------------------------------------- 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: http://www.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- 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: http://www.rcic.com/ click on "Virtual Conference Hall,"
