Teledyne 9110TH - Nitrogen Oxides Analyzer - Manual (Page 325)

ESD Primer Model 9110TH NOx Analyzer
Teledyne Analytical Instruments 305
 Simply touching a grounded piece of metal is insufficient. While this may
temporarily bleed off static charges present at the time, once you stop
touching the grounded metal new static charges will immediately begin to re-
build. In some conditions, a charge large enough to damage a component
can rebuild in just a few seconds.
 Always store sensitive components and assemblies in anti-ESD storage
bags or bins: Even when you are not working on them, store all devices and
assemblies in a closed anti-Static bag or bin. This will prevent induced
charges from building up on the device or assembly and nearby static fields
from discharging through it.
 Use metallic anti-ESD bags for storing and shipping ESD sensitive
components and assemblies rather than pink-poly bags. The famous,
“pink-poly” bags are made of a plastic that is impregnated with a liquid
(similar to liquid laundry detergent) which very slowly sweats onto the
surface of the plastic creating a slightly conductive layer over the surface of
the bag.
While this layer may equalizes any charges that occur across the whole bag, it does
not prevent the build up of static charges. If laying on a conductive, grounded surface,
these bags will allow charges to bleed away but the very charges that build up on the
surface of the bag itself can be transferred through the bag by induction onto the
circuits of your ESD sensitive device. Also, the liquid impregnating the plastic is
eventually used up after which the bag is as useless for preventing damage from ESD
as any ordinary plastic bag.
Anti-Static bags made of plastic impregnated with metal (usually silvery in color)
provide all of the charge equalizing abilities of the pink-poly bags but also, when
properly sealed, create a Faraday cage that completely isolates the contents from
discharges and the inductive transfer of static charges.
Storage bins made of plastic impregnated with carbon (usually black in color) are also
excellent at dissipating static charges and isolating their contents from field effects and
discharges.
 Never use ordinary plastic adhesive tape near an ESD sensitive device or
to close an anti-ESD bag. The act of pulling a piece of standard plastic
adhesive tape, such as Scotch
® tape, from its roll will generate a static
charge of several thousand or even tens of thousands of volts on the tape
itself and an associated field effect that can discharge through or be induced
upon items up to a foot away.
9.4.2. BASIC ANTI-ESD PROCEDURES FOR ANALYZER REPAIR AND
MAINTENANCE
9.4.2.1. Working at the Instrument Rack
When working on the analyzer while it is in the instrument rack and plugged into a
properly grounded power supply.