Blog Archives

What is a Faraday Cage?

by Gene Felder


A Faraday cage or Faraday shield is an enclosure formed by conducting material or by a mesh of such material. Such an enclosure blocks external static and non-static electric fields. Faraday cages are named after the English scientist Michael Faraday, who invented them in 1836. An impressive demonstration of the Faraday cage effect is that of an aircraft being struck by lightning. This happens frequently, but does not harm the plane or passengers. The metal body of the aircraft protects the interior. For the same reason, a car may be a safe place to be in a thunderstorm.


ESD control products that provide a Faraday Cage or shielding include Charleswater Statshield® Metal-In Bags, and Statshield® Metal-Out Bags, Protektive Pak™ impregnated corrugated with shielding layer when using a lid, and Conductive Totes. Charleswater ESD Lab Coats create a Faraday Cage effect around the torso and arms of the operator and shields charges from the operator’s clothing from damaging ESD sensitive devices. (Technically, suppressing the electrical field from clothing worn underneath).


There are standard tests measuring the energy penetration of electrostatic discharges to the interior. The Shielding test method per EN 61340-5-1 Packaging table 4 is ANSI/ESD STM11.31 and the required limit is less than 50 nanoJoules of energy.


The EN 61340-5-1 Edition 1.0 2007-08 Introduction includes “ESD protection can be achieved by enclosing ESD sensitive products in static protective materials, although the type of material depends on the situation and destination. Inside an EPA, low charging and static dissipative materials may provide adequate protection. Outside an EPA, low charging and static discharge shielding materials are recommended.” []

Definitions:
Faraday cage
“A conductive enclosure that attenuates a stationary electrostatic field.”

Electrostatic discharge (ESD) shield
“A barrier or enclosure that limits the passage of current and attenuates an electromagnetic field resulting from an electrostatic discharge.”

Electrostatic shield
“A barrier or enclosure that limits the penetration of an electrostatic field.”

Note: EN 61340-5-1 Edition 1.0 2007-08 can be purchased from the IEC website.

Advertisements

Introducing New ESD White Lab Coats

72120

72125

  • Comfortable ESD dissipative lab coats are ideal for any production environment in which sensitive items (ESDS) are being handled
  • The coats offer ESD protection using the principle of the Faraday cage shielding ESDS from electrostatic charges on operator’s clothing
  • The buttons at the front have an overlap which avoids direct contact with parts

Click here to view New72120

Item Description Price
72120 Female, X – Small £49.29
72121 Female, Small £49.29
72122 Female, Medium £49.29
72123 Female, Large £49.29
72124 Female, X – Large £49.29
Item Description Price
72125 Male, Small £49.29
72126 Male, Medium £49.29
72127 Male, Large £49.29
72128 Male, X – Large £49.29
72129 Male, XX – Large £49.29
Sign up HERE | Request a sample HERE | See list of sales reps and distributors HERE
All items & programs are available through your participating distributor | Submit your questions HERE