On Sun, 09 May 2021 09:57:01 -0400, Paul
wrote:

snip

I wonder if brian put some silver foil on his chair then joined that
to some dangling plug chain that touches the floor via a 10k resistor
(or whatever resistance is normal on such things)?


You could treat the chair with this.

https://www.aclstaticide.com/product...-safety-shield

There's a different product for treating carpeting.
(I hate products you keep having to apply over and
over and over again.)

Quite.

If you're making homemade ESD straps, the dissipation
resistor you want is in the 1 megohm to 22 megohm range.

Aren't there testing stations they use for checking the viability of
ESD gear in such environments?

The 1 megohm one is easier to verify occasionally
with your multimeter, that it's still working.

Sure.

The
purpose of the resistance value, is to reduce the
"peak current" discharged into any semiconductor junctions.

The purpose of the resistance g is to allow a slower dissipation of
the charge energy to minimise high current shock loads AND to ensure
the operator isn't connected to ground with a low resistance path to
increase the risk of electrocution from some live equipment.

The 22 megohm value is the highest resistance
value commonly available at retail.

I know it can be surprisingly high (in normal electronic circuit
terms) because all it needs to do in most cases is 'leak charge' away
from the user, or any charge differential between isolated components
in a safe way.

There was an ESD module in the Novell 'Service and Support' (5 day)
course I used to present when I was a CNI and I used to continually
monitor their use of ESD gear after that module and throughout the
rest of the course.

Roughy ever other week for about 7 years I had 8 delegates strip a PC
down (they worked in pairs) and that included removing the CPU and RAM
from the MOBO and the MOBO from the case etc.

I was away for a week and they got a contractor in. The next week came
in to present another S&S and found 2 of the 4 PC's were dead. (When
you finish presenting your course you reset the room ready for
whatever is going to be in there the next week [1]. If both
instructors are present on the last day then you generally prepped
your own).

I happened to see one of my previous delegates that I'd taken on
another Netware module and he had been on the contractors S&S course
the previous week. I asked if they had been presented with the ESD
module, been issued the ESD kits or been asked to use them during the
course and he said no. As it happened he was a reasonable tech, I had
spare motherboards (as yet unneeded for 7 years) and he helped me get
the two PC's working again with nearly no delay to the start of that
weeks course.

Now, do I know it was poor ESD that killed the two boards? No, but
it's funny they had been ok for all that time before ... ?

Cheers, T i m

[1] The admin staff would come round with a pack of CD's marked to
match the PC's in the room and you would re-image all PC's from the
CD's (it was quicker than pulling the images down from the server).

p.s. If I'm building a PC from scratch I will generally use an ESD
wristband and strap and an ESD mat. If I'm doing general maintenance
on my own gear I will often take a shortcut and just ensure there is
no chance of any static charge differential between any components I
am going to bring together (by having contact to both) and leaving the
machine plugged in but not turned on at the wall.