My first job was in a blasting cap plant in 1960. There were military devices so sensitive they could be set off by turning on a nearby fluorescent desk lamp.
I learned that the human body has a capacitance of 400 pico F. Getting up from a chair could raise a couple of kilovolts. We walked on conductive rubber floors wearing conductive rubber shoes. Bench tops were conductive rubber. Nobody had thought of the wrist strap yet. In those days, rubber was made conductive with carbon black. It was almost as effective as a pencil at marking things. If the anti-static material is not black, maybe it won't be a marking hazard. A megohm and 400 pF has a time constant of 400 microseconds, but you do get the kilovolt spike. The wrist strap looks really good as long as your motion is the only source of static electricity. It keeps your body from ever reaching kilovolt potentials. Bill Hawkins -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Scott Burris Sent: Monday, January 25, 2010 2:11 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Conducting Bench Top Material So looking at ESD mat material at Digikey, there appears to be a bewildering array of choices. Elastomer, rubber, vinyl, thermoplastic, laminate, foam rubber, and polyethelene. Any guidelines about what to choose? Scott _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.