The MIL-STD-285 standard measures the shielding effectiveness in respect to the frequency range from 100 kHz to 10 GHz. All samples that qualify for this testing must be a) some kind of enclosure; b) must be applied as a shield. Some examples of the enclosure vary greatly as there is a vast range of enclosures available. These can include, and are not limited, glass windows, conduit, even nanomaterials such as carbon nanotubes. As long as it will house some kind of material in some capacity, such as a conduit with wire sent through, then the sample would qualify. See the figure below showing an example with conduit. On the transmitting side, the conduit is connected to the test chamber bulk head (access panel) and has a signal being transmitted through it; on the receiving end is the opening of the conduit where the signal is measured to see the signal loss (attenuation) for the overall shielding effectiveness of the sample.
The test setup is the same as other shielding effectiveness, first determining the dynamic range of the unit/sample and the actual measurement of the signal for the sample in question.
Keystone Compliance has the capabilities to test any size of enclosure to MIL-STD-285. We have tested large items such as entire on-site installation buildings and small items that can be easily transported to our lab.
Are you ready to partner with Keystone Compliance to determine the shielding effectiveness of your product when tested to the requirements of MIL-STD 285? Let’s get started!