I also have a copy of those waveforms and a paper Michael King wrote on one of my older Macs, can likely find it if needed. I was lucky to have been mentored by Michael King when I was younger. He is a great scientist/engineer and had a great effect on me.
I was fortunate to have four great mentors in my life: my Father, George Florio (who got me into this field at age ten and helped me to become an engineer by age 14), Henry Ott, and Michael King . I can’t imagine my life without these great men. Maybe others can post about mentors who helped them become engineers. Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: d...@dsmith.org Website: http://dsmith.org On Wed, Jun 20, 2018 at 8:52, John Woodgate <j...@woodjohn.uk> wrote: It's probably not ethnicity directly, but skin resistance. This varies greatly between people. Long years ago, when we had touch-contact channel change on TVs, we had to doubl e the sensitiv ity so that one particular person in the lab could work it. When we took sets to a show, someone tur ned up who couldn't work it. We found it necessary to double the sensitivity again. If you think about a person standing in the ESD field as a large (poorly-) conducting body, you can see why the effect can occur. John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk [http://www.woodjohn.uk] Rayleigh, Essex UK On 2018-06-20 14:06, Jim Hulbert wrote: Somewhere, I have copies of the discharge waveforms (captured on a scope) from human subjects that Michael King recruited during his studies. As I recall, the amplitude of the ESD pulses was limited to about 10kV as the subjects started to balk. I believe Michael’s studies also led to the development of the Andy Hish 255 probe. The waveform from that probe, which was a long wand grasped in the hand, was influenced by the human body capacitance of the technician performing the tests. There was a situation some years ago in our EMC Lab, where my associate and I both consistently passed a product for ESD using the Andy Hish probe, which was our corporate standard tester at the time. However, an intern working with us consistently failed the product. We did our best to make sure we were all following the exact same test technique. The only difference my associate and I could think of was that the intern was of a different ethnicity than us. We didn’t dare mention that, however. Jim Hulbert - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to < emc-p...@ieee.org [emc-p...@ieee.org] > All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html [http://www.ieee-pses.org/emc-pstc.html] Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ [http://product-compliance.oc.ieee.org/] can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ [http://www.ieee-pses.org/] Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) [http://www.ieee-pses.org/list.html] List rules: http://www.ieee-pses.org/listrules.html [http://www.ieee-pses.org/listrules.html] For help, send mail to the list administrators: Scott Douglas < sdoug...@ieee.org [sdoug...@ieee.org] > Mike Cantwell < mcantw...@ieee.org [mcantw...@ieee.org] > For policy questions, send mail to: Jim Bacher < j.bac...@ieee.org [j.bac...@ieee.org] > David Heald < dhe...@gmail.com [dhe...@gmail.com] > - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
