SAE ARP6248

The purpose of this procedure is to establish a technique for reliably and repeatedly measuring the RF shielding characteristics of EMI conductive gasket materials and EMI conductive gaskets. Depending on the materials used for the construction of the measuring setup, the EMI conductive gaskets can be characterized against various joint surfaces. This standard will directly provide shielding effectiveness values up to 40 GHz, and will also be applicable for small samples of conductive EMI gaskets. This new standard is intended to provide a test method to characterize the shielding effectiveness of conductive EMI gaskets, up to the frequency of 40 GHz. FCC recently published EMC emission limits up to this frequency. At this moment (February 2015), standardized methods are only available up to a maximum frequency of 18 GHz. Methods addressing small samples of gaskets are limited up to 10 GHz and are not giving a shielding effectiveness value, but a related parameter called transfer impedance. This standard will directly provide shielding effectiveness values up to 40 GHz, and will also be applicable for small samples of conductive EMI gaskets. A more detailed rationale concerning the validity of some standards is given in Appendix C of this document.