A Practical Shielding Effectiveness Evaluation of EcE Gaskets Incorporating Accelerated Aging

A practical radiating Shielding Effectiveness test fixture is described for evaluating Electrically Conductive Elastomer (EcE) gaskets of the type used to provide protection against electromagnetic interference (EMI). The fixture itself consists of two compartments, each fitted with a broadband antenna. A perimeter gasket of EcE extrusion seals the fixture compartments against a common back-plate. The frequency range of interest is 0.8 to 3.0 GHz. The test fixture is used to generate comparable data describing gasket performance under compression and conditions of accelerated aging, such as elevated temperature and high relative humidity. Measurements of Shielding Effectiveness of several conductive elastomer compositions are described, along with a summary of the advantages and limitations of this type of testing.