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I am not an electrical engineer or technician, just a curious DIYer.

I bought an anti-static wrist strap and when I did the circuit continuity test (using a multimeter) between the end alligator clip that is grounded and the metal button that clips onto the strap, it came negative. That is to say that the two ends of the wrist strap assembly do not have the circuit continuity. I am wondering how will it conduct away the static charge if it is not electrically conductive.

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  • \$\begingroup\$ The idea is control the speed of the charge, you dont want a low ohm ground, you want to control the rate. Like slamming your car into a wall at 50Mph vs taking the time and distance to slow down and just stop at or touch the wall very gently. As you move even if wearing a jacket, sitting on an ESD grounded chair on a floor, with the wrist strap, the whole enchilada you are still generating new charge as you move, you want to control the speed at which that charge dissipates so that it does not rip through the sensitive circuits and cause damage. \$\endgroup\$
    – old_timer
    Commented Nov 9, 2019 at 5:33

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There is typically a 1 megohm resistor between the strap and the cable.

This is to protect the user from being electrocuted if they touch a high(ish) voltage while wearing the strap.

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    \$\begingroup\$ Besides protecting the user, the megohm resistor also protects ESD sensitive devices by limiting static discharge current... \$\endgroup\$
    – bobflux
    Commented Nov 8, 2019 at 23:33
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    \$\begingroup\$ Multimeter conduction beep tests also do not consider things above few hundred ohms as conductive, so the resistance measurement would be the correct setting. \$\endgroup\$
    – Justme
    Commented Nov 9, 2019 at 8:35
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Humans are about 200 picoFarad capacitance to Ground (thru shoe soles).

With 1MegOhm discharge resistor, that's a 200 microsecond tau; if 2,000 volts initially, the 1_TAU would be 37% of 2,000 or 740 volts. THen another Tau to about 300 volts. The 3rs tau to 100 volts.

And all this discharge in only 3*200u or 600uS, or less than 1 MilliSecond.

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