Opinions spought on Electrostatic dissipation·
Russell McMahon email (remove spam text)
I'd be interested in opinions (backed by any available hard data) on what
constitutes an adequate dissipative surface for a storage container used for
I have a number of plastic containers which I wish to use for component
I have lightly sprayed the interior of a number of these with a thin layer
of Nickel spray (intended for EMI/EMC shielding purposes.
While this produces an adequately conductive container, the spray is
horrendously expensive for this purpose and not always readily available.
As a possible alternative I have a rub-on paint like which is intended to
produce a metallic "copper" finish for decorative purposes. It;'s high
density suggests a metallic base. It rubs on to an extremely thing but
opaque and fairly permanent finish. It uses Turpentine as a solvent - this
evaporates rapidly on application.
The resultant finish produces a resistance of around 200 megohms (!!!)
across a 1cm distance using standard meter test probes touching the surface.
(The resistance seems to increase roughly linearly with separation) .
While this is much higher than any normal resistive materials the resistance
is repeatable at various places on the box and at various times. A similar
test under the same humidity conditions on a wooden varnished surface or the
box's raw plastic produces a reading of o/c (>400 Mohm) no matter how close
the probes are brought to each other.
A 1 nanofarad cap would have a discharge time constant of around 0.1s over a
1cm distance or 1 second over a 10cm path.
Is this very high resistance considered adequate for electrostatic
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