MIL-STD-461 for Military EMC & GR-1089-CORE for NEBS Telecom EMC Share Some Requirements

The electromagnetic compatibility (EMC) requirements for telecom and military equipment are considered among the most difficult to meet for any industry.  Not many electronics manufacturers conduct testing for both requirements, but it happens occasionally.  For those who do, it’s an advantage to pursue both at the same time, as there is some overlap.  Following is a short MET Labs overview on some of the primary similarities and differences.

One of MET's ESD Testing Rooms

MIL-STD-461 is the primary EMC standard for military approvals.  The current version is MIL-STD-461F, but previous versions may still be specified in U.S. military contracts. 

GR-1089-CORE is the primary EMC standard for telecommunications (NEBS) equipment.  The current version is Issue 6.

MIL-STD-461  is similar to section 2 and 3 of GR-1089 in that they both include EMC conducted and radiated emissions and susceptibility requirements, however the test methods are quite different.

For emissions, MIL-STD-461 requires use of a peak detector and the limits are more stringent for some platforms, like Army Ground.  On the other hand, the radiated emissions test method could be considered less thorough because the test antenna and EUT are placed in one position, while for GR-1089 radiated emissions, the EUT is rotated 360 degrees and the antenna height is adjusted to find the maximum radiated emissions.

For susceptibility testing, MIL-STD-461 test method CS114 is similar to GR-1089 conducted susceptibility.  Test method CS115 is somewhat similar to GR-1089 section 2 EFT.  RS103 is similar to GR-1089 radiated susceptibility, however, for some military platforms, the test level is much higher than GR-1089 (up to 200V/m).

MIL-STD-461 does not include ESD testing, although many military test programs include IEC 61000-4-2 ESD testing along with -461.  GR-1089 includes ESD testing in section 2 and references IEC 61000-4-2 for the test procedure.

Another occasionally-referenced military standard – MIL-STD-1399-070 DC Mag Field – is not like any GR-1089 test.  This is a 1600A/m DC field, which is quite strong.  If the EUT has no magnetic sensors, compass, or other magnetically sensitive components, it shouldn’t be a problem.  If the EUT does have those components, it would have to be specifically designed to withstand this test.

Read more about testing to MIL-STD-461 or GR-1089-CORE, or request a free quotation for an upcoming test need.

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