John: I faced the same problem about six years ago. I needed to do "verification" in between the expensive annual "calibrations". I first explored the option of buying a Pelligrini Target. As I recall, the quotes I received were around $2000. That seemed outrageous, so I decided to build one myself. I'll bet it took me at least 3 days to make sense of those goofy mechanical drawings in 61000-4-2. If only they had included a photograph or good cross-section in the Standard!
Anyway, I finally figured it out, translated the drawings into something understandable by a U.S. machine shop, and got all the brass parts fabricated locally. It took several in-process consulting sessions with the machinist, but I finally got all the brass parts done for around $300. Then, I purchased a $25 silver electroplating kit. It was like Science Fair time in my workshop! Some hours of painstaking soldering later, the target was completed. I mounted it over a specially-drilled hole in the brass wall panel of our anechoic chamber (you need a Faraday Cage of some sort, and this seemed the easiest). I did a quick check using our Tektronix 1 GHz analog oscilloscope ... and the risetimes and overall waveforms measured within spec! Then, I sent the target to Haefely-Trench for a "calibration" (against their standard Pelligrini target). The results were very, very close. Having performed many verifications at this point, my advice (if you want fairly accurate and repeatable results): 1. Make (or buy) something resembling the 61000-4-2 target. 2. Use a Faraday Cage. 3. Be aware how important the POSITION of the ESD Gun Grounding Strap is to these measurements ... especially to risetime measurements. I always take a photograph of the setup, including the "shape" of the Grounding Strap and where it is attached. If you don't do this, you'll get pretty wild variability between verifications. 4. Even a 500 MHz oscilloscope would probably be OK for "verification". Just make certain that all setup parameters (including Ground Strap placement) are EXACTLY the same each time. That way, if the GUN happens to change, you'll at least know what to do next. Give me a call if you'd like a photo. Good luck! Jim Ericson Quality System Manager/Sr. EMC Engineer Acme Testing Company Acme, WA. 888-226-3837 [email protected] ----- Original Message ----- From: "John Harrington" <[email protected]> To: <[email protected]> Sent: Thursday, May 01, 2003 11:45 AM Subject: ESD gun verification > > Hello All > > Does any one have a quick and dirty (and hopefully cheap) way to verify the > performance of an ESD gun. > > Please, no one suggest building the current sensing system described in the > back of IEC 61000-4-2. I don't understand the drawings let alone have the > workshop or materials to consider it. Although, I may pay someone to build > it for me... > > I am desperate enough to consider buying something off the shelf (if I could > find said shelf). > > All help appreciated > > John Harrington > EMC Technical Manager > F-Squared Laboratories > > ------------------------------------------- > 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: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > Archive is being moved, we will announce when it is back on-line. > All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc > 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
