Some scientific references:
http://www.ce-mag.com/archive/01/Spring/Ogunsola.html
http://www.emcs.org/acstrial/newsletters/winter09/pp2.pdf
The first linked article suggests that currently the only "meaningful" or "appliable" standard is the German Military VG 95373 Part 15:
Quote::
VG 95373 Part 15. This German military standard describes the shielding effectiveness of enclosures.5 The standard covers the frequency range above 30 MHz; between the frequency range of 30 and 200 MHz, a minimum antenna-to-enclosure separation distance of 2.5 m is specified. This distance can be reduced to 1 m for frequencies greater than 200 MHz. The test method specifies that a receiving antenna—which must be small compared with the enclosure under test—be built into the enclosure for the test. Although there are technical problems with this standard, it is currently the only standard applicable to small- and medium-sized enclosures. It is not surprising that the test method described in VG 95373 Part 15 (or variations of it) is used for shielding-effectiveness evaluation of small- and medium-sized enclosures and is favored by manufacturers of conductive plastic enclosures.
Tests like these (examples) made for EMC shielded rack cabinets:
http://www.schroff.co.uk/internet/pdf/EMC_Test_BGT_Rugged_en.pdf
http://web.schroff.de/webcat/subgroup/pdf/varistar_emc_test_e.pdf
http://web.schroff.de/webcat/subgroup/pdf/varistar_emc_test_2_e.pdf
actually make seemingly some sense.
More here:
http://www.schroff.co.uk/internet/html_e/service/testreports/index.html
jaclaz
↧