Teledyne 701 8.5 Basic anti-ESD Procedures for Analyzer Repair and Maintenance

Teledyne API Model 701 Zero Air Generator A Primer on Electro-Static Discharge

01671H (DCN6051) 8-5

 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.

8.5 Basic anti-ESD Procedures for Analyzer Repair and Maintenance

When working on the analyzer while it is in the instrument rack and plugged into a

properly grounded power supply.

1. Attach your anti-ESD wrist strap to ground before doing anything else.