Both Paul and Sandy pointed out that the real issue is the potential difference between you, your tools and the ESD-sensitive components, so a completely "floating" system in which everything on the work area is at the same potential is perfectly safe for the components involved even if no ground is present.
That's true in theory, but I'm personally not comfortable counting on that being the case. For example, my soldering station, along with all of my of my AC powered test equipment, is grounded through the AC mains ground system. So if I, my wrist strap and the components I'm working with are all carrying an electrostatic charge and I pick up my soldering iron by its insulated handle and touch it to a pin of the ESD-sensitive part, that charge will be drained to ground through the iron and sensitive part. The whole system is immediately defeated. My approach is to ensure that the outlet that serves my bench is truly grounded to the AC mains ground and that everything on that bench is connected in parallel to the same ground, including myself through a wrist strap and a 1-megohm resistor. An anti-static pad is nice too. If used it should be connected to the common ground through a 1 megohm resistor as well. The important point about the work surface is to avoid those that collect static charges easily. AVOID such bench coverings as rubber or a piece of carpet! While a wrist strap is a very good investment, its major benefit is to protect you if you forget to ground yourself frequently by touching an unpainted metal ground. Keep in mind that simply squirming around on your chair can produce a destructive charge, so if you don't use a wrist strap, have that ground within easy reach, remember to touch it regularly as you work, use a grounded-tip soldering iron and you'll have no problems with ESD damage. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
