MIL-STD-461 – Electromagnetic Compatibility Testing
MIL-STD-461 was created by the military in 1982, and its charter is to ensure that any electronics procured by the military have very little electromagnetic emissions both radiated through the air and out through power lines and I/O cables. Additionally, it requires that fairly large field strengths do not disrupt the operation of a device. Here are the names of the tests and their purposes:
Table I. Emission and Susceptibility Requirements
| Req. | Description |
| CE101 | Conducted Emissions, Power Leads, 30 Hz to 10 kHz |
| CE102 | Conducted Emissions, Power Leads, 10 kHz to 10 MHz |
| CE106 | Conducted Emissions, Antenna Terminal, 10 kHz to 40 GHz |
| CS101 | Conducted Susceptibility, Power Leads, 30 Hz to 150 kHz |
| CS103 | Conducted Susceptibility, Antenna Port, Intermodulation, 15 kHz to 10GHz |
| CS104 | Conducted Susceptibility, Antenna Port, Rejection of Undesired Signals, 30 Hz to 20 GHz |
| CS105 | Conducted Susceptibility, Antenna Port, Cross-Modulation, 30 Hz to 2- Ghz |
| CS106 | Conducted Susceptibility, Transients, Power Leads |
| CS109 | Conducted Susceptibility, Structure Current, 60 Hz to 100 kHz |
| CS114 | Conducted Susceptibility, Bulk Cable Injection, 10 kHz to 200 MHz |
| CS115 | Conducted Susceptibility, Bulk Cable Injection, Impulse Excitation |
| CS116 | Conducted Susceptibility, Damped Sinusoidal Transients, Cables and Power Leads, 10 kHz to 100 MHz |
| RE101 | Radiated Emissions, Magnetic Field, 30 Hz to 100 kHz |
| RE102 | Radiated Emissions, Electric Field, 10 kHz to 18 GHz |
| RE103 | Radiated Emissions, Antenna Spurious and Harmonic Outputs, 10 kHz to 40 GHz |
| RS101 | Radiated Susceptibility, Magnetic Field, 30 Hz to 100 kHz |
| RS103 | Radiated Susceptibility, Electric Field, 2 MHz to 40 GHz |
| RS105 | Radiated Susceptibility, Transient Electromagnetic Field |
Not all tests are applicable for every product. Your customer’s procurement should provide you with the levels and the applicable tests, but here is a general guideline of what tests are required:
Requirement Matrix
| Equipment and Subsystems Installed In, On, or Launched From the Following Platforms or Installations | Table II. Requirement Applicability |
Legend:
A: Applicable
L: Limited as specified in standard
S: Procuring activity must specify in procurement documentation
Within each set of immunity testing, there are specific field strengths that must be met. Again, this is ultimately dictated by the customer, but here is a guideline for the “RS103” testing levels, which is the radiated immunity test:
TABLE III. RS103 Limits
LIMIT LEVEL (VOLTS / METER)
| FreqRange | Aircraft (External or Safety Critical) | Aircraft Internal | All Ships (Above Decks) & Submarines (External) * | Ships (Metallic) (Below Decks) | Ships (Non-Metallic) (Below Decks) ** | Submarines (Internal) | Ground | Space |
| 2 MHz A | 200 | 200 | 200 | 10 | 50 | 5 | 50 | 20 |
 N
| 200 | 200 | 200 | 10 | 50 | 5 | 10 | 20 |
| 30 MHz AF | 200 | 20 | - | - | - | - | 10 | 20 |
| 30 MHz A | 200 | 200 | 200 | 10 | 10 | 10 | 50 | 20 |
| N
| 200 | 200 | 200 | 10 | 10 | 10 | 10 | 20 |
| 1 GHz AF | 200 | 20 | - | - | - | - | 10 | 20 |
| 1 GHz A | 200 | 200 | 200 | 10 | 10 | 10 | 50 | 20 |
| N
| 200 | 200 | 200 | 10 | 10 | 10 | 50 | 20 |
| 18GHz AF | 200 | 60 | - | - | - | - | 50 | 20 |
| 18GHz A | 200 | 200 | 200 | 10 | 10 | 10 | 50 | 20 |
| N
| 200 | 60 | 200 | 10 | 10 | 10 | 50 | 20 |
| 40GHz AF | 200 | 60 | - | - | - | - | 50 | 20 |
KEY:
A = Army
N + Navy
AF - Air Force
* For equipment located external to the pressure hull of a submarine but within the superstructure, use SHIPS (METALLIC) (BELOW DECKS)
** Equipment located in the hanger deck of Aircraft Carriers
Interested in learning more about the chamber we use for MIL-STD-461 testing? Click here to read about it at our facilities.
As always, we are here to help with the product design cycle to ensure a compliant product. We see compliance issues on a daily basis, and have amassed a great amount of knowledge for solutions we want to share with you. Here is how we can be involved at each stage with our engineering services group.
