MIL-STD-461 is the US Department of Defense's standard governing electromagnetic interference characteristics of military equipment — and unlike most commercial EMC standards, it doesn't bundle requirements into a single combined test. Instead, it defines a library of individually-numbered test methods, each isolating one specific emission or susceptibility mechanism.
The Naming Convention
CE — Conducted Emissions. Tests measuring unwanted electrical noise the equipment puts back onto its own power leads or antenna cabling.
CS — Conducted Susceptibility. Tests verifying the equipment continues to function correctly when interference is injected onto its power leads or cables.
RE — Radiated Emissions. Tests measuring unwanted electromagnetic fields the equipment radiates into the surrounding space.
RS — Radiated Susceptibility. Tests verifying the equipment continues to operate correctly when exposed to externally-applied electromagnetic fields.
The Core Test Methods
| Method | Full name | Frequency range |
|---|---|---|
| CE102 | Conducted Emissions, Power Leads, RF | 10 kHz – 10 MHz |
| RE102 | Radiated Emissions, Electric Field | 10 kHz – 18 GHz |
| RS103 | Radiated Susceptibility, Electric Field | 2 MHz – 18 GHz (40 GHz optional) |
| CS114 | Conducted Susceptibility, Bulk Cable Injection | 10 kHz – 200 MHz |
Why Applicability Varies by Platform
MIL-STD-461 applicability is determined by the specific platform and installation the equipment is intended for — a genuinely different test list applies to a surface ship than to an aircraft, ground vehicle, or submarine.
RE102 and RS103 — Why They Dominate Chamber and Amplifier Selection
RE102 measures radiated electric field emissions across 10 kHz to 18 GHz. RS103 applies a defined electric field strength (typically 20–200 V/m) across 2 MHz to 18 GHz, using a calibrated transmit antenna, signal source, and power amplifier. RS103 can also be performed using a mode-tuned reverberation chamber as an alternative.
A Practical Note on Tailoring
MIL-STD-461's appendix explicitly anticipates that the default test requirements may be tailored by the procuring activity for a specific program. RE102 is widely cited as one of the most commonly failed tests in military and aerospace programs.