Everything you need to know about MIL-STD-461

MIL-STD-461 is a common requirement for military programs and systems that provides guidance on EMI/ EMC verification requirements for all equipment and subsystems procured by military equipment. In this news article, we will discuss the MIL-STD-461 test and the importance of electromagnetic compatibility.

Note: Expando is not a compliance testing facility. Our products are rugged servers and workstations that comply with military and industrial standards. We have  partners and suppliers that can assist you with your testing needs.

What is the MIL-STD-461 test?

MIL-STD-461 is a military and defense equipment testing standard that was first released in 1967. This test assures that the ruggedized computer systems can function properly within electromagnetic (EM) environments and avoid releasing EM energy that could potentially cause EM Interference (EMI) with nearby devices.

Electromagnetic interference, also called radio-frequency interference when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction.

It is worth mentioning, that since its initial publication in 1967, MIL-STD-461 has undergone a total of seven revisions:

MIL-STD-461A (1968)
MIL-STD-461B (1980)
MIL-STD-461C (1986)
MIL-STD-461D (1993)
MIL-STD-461E (1999)
MIL-STD-461F (2007)
MIL-STD-461G (2015)

Why is MIL-STD-461 important?

MIL-STD-461 is critical for mission success and safety. As the number of space-constrained programs and applications that use several embedded computer systems grows, so does the likelihood of EMI between them. Given that our mission-critical servers and workstations power high-stakes military systems and applications, military personnel need assurance that their systems will not be disturbed by EMI.

If a rugged server or workstation isn’t MIL-STD-461 compliant but is used in a mission-critical system, there’s a higher risk of mission disruption, mission failure, and even data loss, all of which can have severe consequences, especially when national security is at stake. Below you can a few purposes of this test:

• Ensures the equipment is electromagnetically compatible with its installation environment
• Equipment shall not interfere with the operation of other equipment
• Equipment shall operate reliably and as designed in the presence of the electromagnetic sources within its installation environment

What tests are in MIL-STD-461?

MIL-STD-461 test procedures are designated by an alphanumeric coding system. And each MIL-STD-461 requirement is identified by a three-digit number succeeding a two-letter combination.

• Conducted emissions requirements are designated by CE
• Radiated emissions requirements are designated by RE
• Conducted susceptibility requirements are designated by CS
• Radiated susceptibility requirements are designated by RS

Conducted emissions refer to EM energy generated by a system or device and transmitted through its power cord via an electric current. Radiated emissions, on the other hand, refer to the unintentional generation of EM energy from a system or device.

Moreover, conducted susceptibility and radiated susceptibility refers to a device’s or system’s vulnerability to conducted and radiated emissions, respectively. These can also be referred to as conducted immunity and radiated immunity, which instead specifies a system’s or device’s resistance to both types of emissions.

Introducing partners or suppliers

Expando has partners and suppliers that are qualified to perform the tests and we are happy to guide you on that.

If your rugged server or workstation is expected to operate in proximity to any number of electrical and electronic systems, a MIL-STD-461 compliance certification is a must. That is why Expando assures our products to be MIL-STD-461 certified.
Check out our next news article on the MIL-STD-810 series if you’re interested in learning more about military and industrial standards.

Contact us for price questions and technical solutions at info@expando.se or call us at +46 (0)8-544 900 44.