Design practices for military emc and environmental compliance

Design Practices for Military EMC andEnvironmental Compliancewww.intertek.com/emc/military-aerospace

I. BackgroundThe reliable operation of complex electronic communications, control and armament systems inextreme environments demands stringent design criteria and careful validation. Severe shock,vibration, heat, humidity and airborne contaminants are common in land, sea and air platforms.Coupled with dense packaging, high-power radio and radar illumination, Hazards ofElectromagnetic Radiation to Ordnance (HERO), and a possible electromagnetic pulse (EMP), themilitary equipment environmental requirements can extreme indeed. In order to expedite equipment availability and reduce cost, the acquisition of commercial-off-the-shelf (COTS) equipment for US military applications is an attractive consideration. But many types of commercial equipment are unlikely to meet all military environmental requirements as manufactured, so some modification or re-design is usually needed. Defining the gap between the commercial equipment’s environmental performance and its military expectationsis a first step in determining its potential suitability.The full cycle of US military product development from environmental assessment, to definition ofrequirements, to test reports, is carefully spelled out in the relevant military standards or ancillarydocuments for the applicable physical and electromagnetic environments. These provide the designguidance, along with competent engineering practices, for a cost-effective and robust militaryproduct design.II. The Electromagnetic EnvironmentElectromagnetic compatibility (EMC) requires the component, equipment or system to perform itsdesigned functions without causing or suffering unacceptable degradation due to electromagneticinterference to or from other equipment. The starting point for EMC is self-compatibility, where thefinal product or system does not interfere with its own operation. This is a basic requirement inmilitary EMC standards; for example, in MIL-STD-461F clause 4.2.3: The operational performance of an equipment or subsystem shall not be degraded, nor shall it malfunction, when all of the units or devices in the equipment or subsystem are operating together at their designed levels of efficiency or their design capability.As we shall see, this is the modest starting point for military EMC, which extends to both lower andhigher frequencies than most commercial EMC standards and to both lower emission limits andmuch higher susceptibility requirements. Test methods generally differ from their commercialcounterparts in both setup and detail. A. History of military EMCEMC problems in commercial applications were first noted worldwide in the 1930’s, when earlybroadcast radios were being installed in automobiles. Reception was degraded by ignition noiseand electrostatic buildup caused by non-conductive rubber tires.www.intertek.com/emc/military-aerospace

The first US military specification on EMC also addressed this problem. It was published by the USArmy Signal Corps in 1934 as SCL-49, "Electrical Shielding and Radio Power Supply in Vehicles". Itrequired shielding of the vehicle ignition system, regulator and generator. With the increased use ofmobile military radio communications, SCL-49 became inadequate. In 1942 it was superseded byspecification 71-1303, "Vehicular Radio Noise Suppression." In the period 1950 - 1965, each major military agency imposed its own EMC specifications. The Air Force used MIL-I-6181 and MIL-I- 26600; the Navy used MIL-I-16910; the Army used MIL-I-11748 and MIL-E-55301(EL). These specifications limited the levels of conducted and radiated emissions, and they set susceptibility levels which systems and equipment must reject. These specifications also detailed the test configurations and methods for demonstrating compliance.Unfortunately, over this period of time the various military EMC standards diverged from eachother in test frequency ranges, limits and required test equipment. The differences made it quiteexpensive for a test lab or manufacturer to be fully equipped to test to all EMC specifications.In 1960 the US Department of Defense enacted acomprehensive electromagnetic compatibilityprogram that charged the military services to buildEMC into all of their communications and electronicsequipment. In 1966, EMC personnel of the threemilitary departments jointly drafted standardsaddressing the overall EMC needs of the Departmentof Defense. That program resulted in 1967 in militarystandards 461 (requirements), 462 (methods) and463 (definitions and acronyms). After revision, MIL-STD-461A was issued in August 1968. Subsequentrevisions were designated B, C, and D. MIL-STD-463was withdrawn after 1990.In 1999 the 461D and 462D standards were merged into one document, MIL-STD-461E. Thecurrent version is MIL-STD-461F (2007), and updates to it are in the planning stage. Prior revisionlevels A-E may still be specified for testing. B. USA: Supporting documentationThe designer of military electronic equipment has an abundance of guidance available forsuccessfully meeting the EMC demands of the intended operating environments. 1. StandardsActive military standards (Table 1) specify a variety of scopes, environmental sub-categories, limitsand test methods clearly and in great detail.www.intertek.com/emc/military-aerospace

reference title Grounding, Bonding and Shielding for Common Long Haul/Tactical Communications Systems Including MIL-STD-188-124 Ground Based Communication-Electronics Facilities and Equipments High-Altitude Electromagnetic Pulse (HEMP) Protection For Ground-Based C41 Facilities Performing Critical, MIL-STD-188-125-1 Time-Urgent Missions - Part 1 - Fixed Facilities High-Altitude Electromagnetic Pulse (HEMP) Protection For Ground-Based C4I Facilities Performing Critical, MIL-STD-188-125-2 Time-Urgent Missions - Part 2 - Transportable Systems MIL-STD-331C Environmental and Performance Tests for Fuze and Fuze Components MIL-STD-449D Measurement of Radio Frequency Spectrum Characteristics MIL-STD-461F Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment MIL-STD-464A Electromagnetic Environmental Effects – Requirements for Systems MIL-STD-704F Aircraft electric Power Characteristics Shipboard Bonding, Grounding, and other Techniques for Electromagnetic Compatibility, Electromagnetic MIL-STD-1310H Pulse (EMP) Mitigation, and Safety Measurement of effectiveness of cable, connector, and weapons enclosure shielding and filters in precluding MIL-STD-1377 Hazards of electromagnetic radiation to ordnance DOD-STD-1399-70-1 Interface Standard for Shipboard Systems – Section 070 – Part 1 – DC Magnetic Field Environment MIL-STD-1399-300B Interface Standard for Shipboard Systems – Section 300 - Electric Power, Alternating Current MIL-STD-1541A Electromagnetic Compatibility Requirements for Space Systems MIL-STD-1542B Electromagnetic Compatibility and Grounding Requirements for Space System Facilities MIL-STD-1576 Electroexplosive Subsystem Safety Requirements and Test Methods for Space Systems MIL-STD-1605A Procedures for Conducting a Shipboard Electromagnetic Interference (EMI) Survey (Surface Ship) MIL-STD-2169B High Altitude Electromagnetic Pulse (HEMP) Environment. Table 1 Active US military EMC standards for equipment, systems and facilities.The most commonly-used MILstandards are 461 (subsystemsand equipment) and 464(systems), and they apply toground-based, shipboard andairborne applications. Othergovernment documents mayapply to a specific platform orapplication, and some of theseare listed in the standards suchas MIL-STD-461 and -464. 2. HandbooksIn addition to the EMC standards listed in Table 1, there are a number of handbooks available thatprovide procedural, EMC assessment and design guidance for specific military applications. Theseprovide guidance only, and are not to be construed as requirements. A list of relevant handbooks isgiven in Table 2 below.www.intertek.com/emc/military-aerospace

reference title Electromagnetic (Radiated) Environment Considerations for Design and Procurement of Electrical and Electronic MIL-HDBK-235B Equipment, Subsystems and systems MIL-HDBK-237D Electromagnetic Environmental Effects and Spectrum Supportability Guidance for the Acquisition Process MIL-HDBK-240 Hazards of Electromagnetic Radiation to Ordnance (HERO) Test Guide MIL-HDBK-274 Electrical Grounding for Aircraft safety MIL-HDBK-419A Grounding, Bonding and Shielding for Electronic Equipments and Facilities, Volume 1 of 2 Basic Theory High-Altitude Electromagnetic Pulse (HEMP) Protection for Fixed and Transportable Ground-Based C4 1 Facilities MIL-HDBK-423 – Volume 1 – Fixed Facilities MIL-HDBK-454B General Guidelines for Electronic Equipment MIL-HDBK-83575 General Handbook for Space Vehicle Wiring Harness Design and Testing MIL-HDBK-83578 Criteria for Explosive Systems and Devices used on Space Vehicles Table 2 Active US military handbooks relating to EMC.Generally these handbooks are tutorial in nature, clearly written, and with explanations of theunderlying physical principles. They provide invaluable assistance to the equipment or systemsdesigner. 3. Data Item DescriptionsFinally, there are very detailed documentation specifications associated with military EMCstandards. In some cases the required documentation is described in separate Data ItemDescriptions (DIDs) or Test Operational Procedures (TOPs). These Data Item Descriptions cover EMCdesign procedures, test and verification procedures, and test reports. Table 3 contains a list of DataItem Descriptions and TOPs and the military standards with which they are associated. reference Title associated withDI-EMCS-80199C Electromagnetic Interference Control Procedures (EMICP) MIL-STD-461FDI-EMCS-80200C Electromagnetic Interference Test Report (EMITR) MIL-STD-461FDI-EMCS-80201C Electromagnetic Interference Test Procedures (EMITP) MIL-STD-461F Engineering/manufacturingDI-EMCS-81295A Electromagnetic Effects Verification Procedures (EMEVP) development phase - any Demo of life cycle EMCDI-EMCS-81528 Electromagnetic Compatibility Program Procedures compliance - any Electromagnetic Environmental Effects (E3) Integration and Analysis ReportDI-EMCS-81540A MIL-STD-464A (E31AR)DI-EMCS-81541A Electromagnetic Environmental Effects (E3) Verification Procedures (E3VP) MIL-STD-464ADI-EMCS-81542A Electromagnetic Environmental Effects (E3) Verification Report (E3VR) MIL-STD-464ADI-EMCS-81777 Electromagnetic Interference Survey (EMIS) Test Report MIL-STD-1605ADI-EMCS-81782 Electromagnetic Interference Survey (EMIS) Test Procedures MIL-STD-1605ATOP-1-2-511 Electromagnetic Environmental Effects System Testing MIL-STD-464A MIL-STD-464A andTOP 1-2-622 Vertical Electromagnetic Pulse (VEMP) Testing MIL-STD-2169B Table 3 EMC Data Item Descriptions and Test Operational Procedures.For example, the Data Item Description DI-EMCS-80199C associated with standard MIL-STD-461F isvery explicit in the level of detail to be provided regarding equipment design procedures:www.intertek.com/emc/military-aerospace

3.2. Design techniques and procedures. The EMICP [Electromagnetic Interference Control Procedures] shall describe the specific design techniques and procedures used to meet each emission and susceptibility requirement, including the following: a. Spectrum management techniques. b. EMI mechanical design, including the following: (1) Type of metals, casting, finishes, and hardware employed in the design. (2) Construction techniques, such as isolated compartments; filter mounting, isolation of other parts; treatment of openings (ventilation ports, access hatches, windows, metal faces and control shafts), and attenuation characteristics of Radio Frequency (RF) gaskets used on mating surfaces. (3) Shielding provisions and techniques used for determining shielding effectiveness. (4) Corrosion control procedures. (5) Methods of bonding mating surfaces, such as surface preparation and gaskets. c. Electrical wiring design, including cable types or characteristics, cable routing, cable separation, grounding philosophy, and cable shielding types and termination methods. d. Electrical and electronic circuit design, including the following: (1) Filtering techniques, technical reasons for selecting types of filters, and associated filter characteristics, including attenuation and line-to-ground capacitance values of AC and DC power line filters. (2) Part location and separation for reducing EMI. (3) Location, shielding, and isolation of critical circuits.This DID also requires, among other items, analysis (results demonstrating how each applicablerequirement is going to be met) and developmental testing (testing to be performed duringdevelopment such as evaluations of breadboards, prototypes, and engineering models). For theequipment designer, these points to be documented constitute a virtual punch list of EMC designattributes. C. MIL-STD-461F – EMC for subsystems and equipmentThis is no doubt the most widely-used standard for US military EMC assessment. Specific testrequirements are grouped according to conducted (C) or radiated (R) coupling, and emissions (E) orsusceptibility (S). Thus the tests are designated: Conducted emissions: CE--- Radiated emissions: RE--- Conducted susceptibility: CS--- Radiated susceptibility: RS---The dashes are replaced by the test reference number. Over time, the numerical test designationshave transitioned from 01 to 101, 02 to 102, etc., but the prefixes have remained constant. Table 4indicates the changes in MIL-STD-461 test requirements from versions A through E, and Table 5reflects the present version F requirements. Not all tests apply to all platforms or environments;Table 6 summarizes test applicability.ESD and lightning effects are not included in MIL-STD-461F, although they are being discussed forinclusion in the next (G) version. ESD and lightning protection are covered in MIL-STD-464A, and inthe current US standard for commercial aircraft equipment DO-160F, “Environmental Conditionswww.intertek.com/emc/military-aerospace

and Test Procedures for Airborne Equipment.” DO-160F contains a number of non-EMCenvironmental requirements, and equipment qualified to revisions C – F of RTCA DO-160 is oftensuitable for military aircraft applications. A summary of DO-160F test categories is given in Table 7.The military electronic equipment designer needs to know the types of EMC tests that will beapplied to the equipment, the magnitudes or limits of the tests, and the frequency ranges of thetests, in order to design for compliance. The designer also needs to know that, where theequipment will be used in more than one environment, the most stringent requirements apply.Generally of secondary importance to the designer are the test configuration details, which areamply documented in MIL-STD-461F. These test details are of course essential to the testingpersonnel.What is important to the equipment designer, for the purpose of understanding the limits, are theradiated emissions test distances – which differ from the normal commercial separations of 3m or10m. MIL-STD-461F is almost unique among EMC standards in requiring a 1m distance betweenthe electric field antenna and the test setup boundary (RE102). Only DO-160F has a similar radiatedemissions test distance. The magnetic field measurement distance in RE101 is 7 cm. Figure 1 RE102 test setup showing 1m antenna distance, from MIL-STD-461Fwww.intertek.com/emc/military-aerospace

MIL-STD-461A MIL-STD-461B/C MIL-STD-461D MIL-STD-461E test description frequency test description frequency test description frequency test description frequencyCE01 Power Leads 30 Hz-20 kHz CE01 Power / Signal Leads 30 Hz-15 kHz CE101 Power Leads 30 Hz-10 kHz CE101 Power Leads 30 Hz-10 kHzCE02 Control / Signal Leads 30 Hz-20 kHz CE02 N/ACE03 Power Leads 20 kHz-50 MHz CE03 Power/Signal Leads 15 kHz-50 MHz CE102 Power Leads 10 kHz-10 MHz CE102 Power Leads 10 kHz-10 MHzCE04 Control / Signal Leads 20 kHz-50 MHz CE04 N/ACE05 Inverse Filter Method 30 Hz-50 MHz CE05 N/ACE06 Antenna Terminal 10 kHz-10 GHz CE06 Antenna Terminal 10 kHz-26 GHz CE106 Antenna Terminal 10 kHz-40GHz CE106 Antenna Terminal 10 kHz-40GHz Spikes / TimeCE07 N/A CE07 Power Leads DomainCS01 Power Leads 20 Hz-50 kHz CS01 Power Leads 30 Hz-50 kHz CS101 Power Leads 30 Hz-50 kHz CS101 Power Leads 30 Hz-150 kHzCS02 Power Leads 50 kHz-400 MHz CS02 Power Leads 50 kHz-400 MHzCS03 Intermodulation 15 kHz-10 GHz CS03 Intermodulation 15 kHz-10 GHz CS103 Antenna Port-Intermod 15 kHz-10 GHz CS103 Antenna Port-Intermod 15 kHz-10 GHz Antenna Port-Rejection of Antenna Port-Rejection.CS04 Undesired Signal Rejection 15 kHz-10 GHz CS04 Undesired Sig. Rejection 30 kHz-20 GHz CS104 30 Hz -20 GHz CS104 30 Hz -20 GHz Undesired Signals of Undesired Signals Antenna Port-Cross Antenna Port-CrossCS05 Cross Modulation 15 kHz - 10 GHz CS05 Cross Modulation 30 kHz - 20 GHz CS105 30 Hz-20 GHz CS105 30 Hz-20 GHz Modulation Mod.CS06 Spikes, Power Leads CS06 Spikes, Power LeadsCS07 Squelch Circuits CS07 Squelch CircuitsCS08 Undesired Sig. Rejection 30 Hz-10 GHz CS08 N/A Structure Common ModeCS09 N/A CS09 60 Hz-100 kHz Current Damped SinusoidalCS10 N/A CS10 10 kHz-100 MHz Transients (terminals)RE01 Magnetic Field 30 Hz-50 kHz RE01 Magnetic Field 30 Hz-50 kHz RE101 Magnetic Field 30 Hz-100 kHz RE101 Magnetic Field 30 Hz-100 kHzRE02 Electric Field 14 kHz-10 GHz RE02 Electric Field 14 kHz-10 GHz RE102 Electric Field 10 kHz-18 GHz RE102 Electric Field 10 kHz-18 GHz Antenna Spurious & Antenna Spurious &RE03 Spurious & Harmonic 10 kHz-40 GHz RE03 Spurious & Harmonic 10 kHz-40 GHz RE103 10 kHz-40 GHz RE103 10 kHz-40 GHz Harmonics HarmonicsRE04 Magnetic Field 20 Hz-15 kHz RE04 N/ARE05 Vehicle & Eng. Equipment 150 kHz-1 GHz RE05 N/ARE06 Overhead Powerlines 14 kHz-1 GHz RE06 N/A Magnetic Field, Equipment Magnetic Field, Magnetic Field,RS01 Magnetic Field 30 Hz-30 kHz RS01 30 Hz-50 kHz RS101 30 Hz-100 kHz RS101 30 Hz-100 kHz and Cables Equipment and Cables Equipment and Cables Powerline & Magnetic Induction, Powerline &RS02 Magnetic Induction RS02 Spike Equipment and Cables Spike Electric Field, Equipment Electric Field, Equipment Electric Field, EquipmentRS03 Electric Field 14 kHz-10 GHz RS03 14 kHz-40 GHz RS103 10 kHz-40 GHz RS103 2 MHz-40 GHz and Cables and Cables and CablesRS04 Parallel Line Fields 14 kHz-30 MHz RS04 N/A Transient Electromagnetic Transient ElectromaneticRS05 N/A RS05 Electromag Pulse Field Transients RS105 Transients RS105 Transients Field Field CS109 Structure Current 60 Hz-100 kHz CS109 Structure Current 60 Hz-100 kHz CS114 Bulk Cable Injection 10 kHz-400 MHz CS114 Bulk Cable Injection 10 kHz-200 MHz CS115 Bulk Cable Injection Impulse CS115 Bulk Cable Injection Impulse Sine Transients - Cables, Sine Transients - Cables, CS116 10 kHz-100 MHz CS116 10 kHz-100 MHz and Power Leads and Power Leads Table 5 MIL-STD-461 requirement changes, versions A – E.www.intertek.com/emc/military-aerospace

Lowest emission or Changes from 461ETest Description highest version susceptibilityCE101 Conducted Emissions, Power Leads, 30 Hz to 10 kHz 76 dBµA -CE102 Conducted Emissions, Power Leads, 10 kHz to 10 MHz 60 dBµV - Conducted Emissions, Antenna Terminal, 10 kHz to 40 34 dBµVCE106 - GHz Applicability added for surface Conducted Susceptibility, Power Leads, 30 Hz to 150CS101 136 dBµV ships; setup modifications kHz suggested. Conducted Susceptibility, Antenna Port, Per procurementCS103 - Intermodulation, 15 kHz to 10 GHz specification Conducted Susceptibility, Antenna Port, Rejection of Per procurementCS104 - Undesired Signals, 30 Hz to 20 GHz specification Conducted Susceptibility, Antenna Port, Cross- Per procurementCS105 - Modulation, 30 Hz to 20 GHz specificationCS106 Conducted Susceptibility, Transients, Power Leads 400 V peak CS06 absent from E, added back. Conducted Susceptibility, Structure Current, 60 Hz toCS109 120 dBµA - 100 kHz Conducted Susceptibility, Bulk Cable Injection, 10 kHz Adds common mode test for someCS114 109 dBµA to 200 MHz applications. Conducted Susceptibility, Bulk Cable Injection, ImpulseCS115 5A x 30 ns - Excitation Conducted Susceptibility, Damped Sinusoidal Testing with power off is deleted;CS116 Transients, Cables and Power Leads, 10 kHz to 100 10 A peak procedure allows reduction of MHz calibrated test signal if necessary. Test procedure is modified to allowRE101 Radiated Emissions, Magnetic Field, 30 Hz to 100 kHz 76 dBpT @ 7 cm separations > 7cm where non- compliances are noted. Applicability and frequency rangesRE102 Radiated Emissions, Electric Field, 10 kHz to 18 GHz 24 dBµV/m @ 1m modified. Rod antenna methods modified. Radiated Emissions, Antenna Spurious and HarmonicRE103 -80 dBc, far field Minor test procedure changes. Outputs, 10 kHz to 40 GHz Radiated Susceptibility, Magnetic Field, 30 Hz to 100 180 dBpT Scan rate is reduced.RS101 kHz Radiated Susceptibility, Electric Field, 2 MHz to 40 GHz 200 V/m Sensor placement clarified;RS103 radiating antenna distance limited to > 1m.RS105 Radiated Susceptibility, Transient Electromagnetic Field 50 kV/m peak - Table 6 MIL-STD-461F requirement changes from versions E to F (2007).In addition to the changes noted in the table above, MIL-STD-461F addresses several topics ofgeneral applicability: - The requirement to qualify “Line-Replaceable Modules (LRMs)” is added; - Restricts the testing of shielded power cables; - Includes software in the requirement to verify test procedures; - Frequency step size above 1 GHz has been increased for susceptibility testing.www.intertek.com/emc/military-aerospace

Simultaneously with the publication of the F version of MIL-STD-461 (December 2007), the Fversion of RTCA DO-160 was published. DO-160F also includes, for the first time, the CS106 testthat was originally in MIL-STD-461 but later deleted only to be restored in the latest version. General Section 1.0 Purpose and Applicability Section 2.0 Definition of Terms - General Section 3.0 Conditions of Tests Environmental requirements Section 4.0 Temperature and Altitude Section 5.0 Temperature Variation Section 6.0 Humidity Section 7.0 Operational Shocks and Crash Safety Section 8.0 Vibration Section 9.0 Explosion Proofness Section 10.0 Waterproofness Section 11.0 Fluids Susceptibility Section 12.0 Sand and Dust Section 13.0 Fungus Resistance Section 14.0 Salt Spray Section 24.0 Icing Section 26.0 Fire, Flammability EMC requirements Section 15.0 Magnetic Effect Section 16.0 Power Input Section 17.0 Voltage Spike Section 18.0 Audio Frequency Conducted Susceptibility – Power Inputs Section 19.0 Induced Signal Susceptibility Section 20.0 Radio Frequency Susceptibility (Radiated and Conducted) Section 21.0 Emission of Radio Frequency Energy Section 22.0 Lightning Induced Transient Susceptibility Section 23.0 Lightning Direct Effects Section 25.0 Electrostatic Discharge Table 7 EMC and environmental requirements in RTCA DO-160F.RTCA DO-160F includes the ESD and lightning requirements currently absent from MIL-STD-461F,and it includes the environmental requirements which are found in separate MIL documentsdiscussed below. The European Union version of DO-160F is EUROCAE/ED-14F, which is identicallyworded. D. MIL-STD-464A – EMC requirements for systemsThis standard establishes electromagnetic environmental effects (E3), interface requirements andverification criteria for airborne, sea, space, and ground systems, including associated ordnance.MIL-STD-464A contains two sections, the main body and an appendix. The main body of thestandard specifies a baseline set of requirements. The appendix portion provides a detailedrationale and guidance, so that the baseline requirements can be tailored for a particularapplication.Verification is intended to cover all life cycle aspects of the system. This includes (as applicable)normal in-service operation, checkout, storage, transportation, handling, packaging, loading,unloading, launch, and the normal operating procedures associated with each aspect.The scope of E3 as used in this standard is very broad: all electromagnetic disciplines, includingelectromagnetic compatibility; electromagnetic interference; electromagnetic vulnerability;www.intertek.com/emc/military-aerospace

electromagnetic pulse; hazards of electromagnetic radiation to personnel, ordnance, and volatilematerials; and natural phenomena effects of lightning and static.Margin requirements apply to all EMC related tests performed in a 464A verification exercise. Theintent is to account for manufacturing variations, aging and maintenance to assure that allequipment, not just test samples, will be compliant in the field over the equipment lifetime.Additional compliance margins to the limits specified in the standard are required for safety-critical, mission-critical and electrically-initiated devices (EIDs) such as electroexplosive devices andfusible links. The additional margins are: - > 6 dB for safety critical and mission critical system functions; - > 16.5 dB of maximum no-fire stimulus for safety assurances; - > 6dB of maximum no-fire stimulus for other purposes.The worst-case (lowest emission limit or highest susceptibility requirement) for the environmentscategorized in MIL-STD-464A are summarized in Table 8 below. In many cases the requirementsare frequency-dependent, and are much lower than worst-case over much of the frequency range.The standard should be consulted for details and definitions. Lowest emission or highest clause parameter susceptibility 5.2 Intra-system EMC (see also MIL-STD-461F clause 4.2.3) Self-compatibility 5.2.1 Hull-generated intermodulation interference (IMI) Not detectable by onboard receivers 5.2.2 Shipboard internal electromagnetic environment (EME). 50 V/m 5.2.3 Multipaction, space applications, equipment and subsystems No effect External RF electromagnetic environment (EME) Flight deck, ships 2030 V/m peak, 200 V/m average Weather deck, ships 2030 V/m peak, 200 V/m average Main beam of transmitter, ships 27460 V/m peak, 2620 V/m average 5.3 Space and launch vehicle systems 200 V/m peak, 200 V/m average Ground systems 2500 V/m peak, 50 V/m average Army rotary wing aircraft 27460 V/m peak, 3120 V/m average Fixed wing aircraft, excluding shipboard 7200 V/m peak, 1050 V/m average Lightning 5.4 Severe stroke 200kA strike, 100 kA restrike Near strike 2.2 x 109 A/m/s @ 10m 5.5 Electromagnetic pulse (EMP) per MIL-STD-2169B classified 5.6 Subsystems and equipment EMI Per MIL-STD-461F System operational performance 5.6.1 Non-developmental items (NDI) and commercial items requirements shall be met. 5.6.2 Shipboard DC magnetic field environment. See MIL-STD-1399, Section 070 Electrostatic charge control. Vertical lift and in-flight refueling. 300 kV discharge 5.7 Precipitation static (p-static) control Meet operational requirements Ordnance subsystems. 25 kV discharge Electromagnetic radiation hazards (EMRADHAZ) Hazards of electromagnetic radiation to personnel (HERP). See DoDI 6055.11 5.8 Hazards of electromagnetic radiation to fuel (HERF) No inadvertent ignition Hazards of electromagnetic radiation to ordnance (HERO). 27460 V/m peak, 2620 V/m average 5.10.3 Mechanical interfaces – DC bonding levels 2.5 – 15 m Aircraft grounding jacks – resistance between the mating plug 5.11.1 <1 and the system ground reference. 2 5.13 Emissions control (EMCON) < 105 dBm/m @ 1 km, 500 kHz – 40 GHz Table 8 Summary of MIL-STD-464A requirements. The high field strength susceptibility values occur in radar bands.www.intertek.com/emc/military-aerospace

E. MIL-STD-1310H – shipboard bonding, grounding and other techniques for EMC This document specifies standard practices in wiring, bonding, grounding and shielding to facilitate achievement of the intra-ship and inter-ship electromagnetic compatibility (EMC), electromagnetic pulse (EMP), bonding, and intermodulation interference (IMI) requirements of MIL-STD-464A. It applies to metal and nonmetallic hull ships and is applicable during ship construction, overhaul, alteration, and repair. MIL-STD- 1310H is not a typical EMC standard, but it provides the methods guidance appropriate to obtaining EMC in the shipboard environment. This revision of MIL-STD-1310 has been expanded to include procedures for Electromagnetic Pulse (EMP) hardening. It also provides procedures and guidance to more easily address MIL-STD-464A requirements in relationship to intra- and inter-ship EMC, hull-generated IMI, lifecycle electromagnetic environmental effects (E3) hardness, EMP, and electrical bonding. A separate appendix is included, with procedures to identify whether commercial-off-the-shelf equipment (COTS) or non-developmental items (NDI) meets appropriate safety requirements before use, and to providedirection to bring them into conformance when necessary. F. MIL-STD-1541A – space systemsThe requirements covered by this standard apply to launch and space vehicles plus the associatedgrounds airborne, or spaceborne operational and support elements of the space system. It appliesto new and modified or redesignedequipment or systems, and to existingequipment used in new applications.MIL-STD-1541A establishes theelectromagnetic compatibility requirementsfor space systems, including frequencymanagement, and the related requirementsfor the electrical and electronic equipmentused in space systems. It also includesrequirements designed to establish aneffective ground reference for the installedequipment and designed to inhibit adverseelectrostatic effects. Bonding and preventionof electrostatic buildup are covered in detail.As with MIL-STD-464A, this standard imposes additional compliance margin requirements incritical situations:www.intertek.com/emc/military-aerospace

Category I: Serious injury or loss of life, damage to property, or 12 dB for major loss or delay of mission capability qualification; 6 dB for acceptance Category II: Degradation of mission capability, including any 6 dB loss of autonomous operational capability Category III: Loss of functions not essential to mission 0 dBIntersystem and intrasystem analysis is required by the standard, which also references all emissionand susceptibility requirements in MIL-STD-461 (as modified by MIL-STD-1541A) for the relevantclass of equipment. Some of the specific requirements of this standard not covered in MIL-STD-461 are summarized in Table 9 below. Thorough qualification testing is emphasized in thestandard. section test limit 5.2.5 Lightning protection 200 kA peak Outer surface resistivity of ESD control Grounded semiconductive coating over insulating material < 108 /square 5.2.6 Painted surface over grounded semiconductive material-over < 4.6 x 107 /square dielectric (2.5/t) x 1010 -cm Volume resistivity of a coating( t, cm) over a grounded metal conductor Electrical power quality Voltage ripple < 500 mV peak-to-peak Spikes < 3 times nominal load, < 0.14 x 10-3 V-s Surges Return to steady-state in 5 ms (+) and 100 ms 5.2.10 Load switching and load faults (-) Power subsystem faults – surge amplitude Remain within 65% to 130% of nominal Vehicle power output ground isolation Remain within 0% to 175% of nominal >1M Performance criteria – MIL-STD-461 applies as noted CE01 applies CE06 and RE03 apply Frequency extended to 30th harmonic or 100 5.3.3 CS01 limit applies GHz CS02 and RS03 apply Test under maximum and minimum supply CS06 limits Susceptibility signals chosen for max. effect 200 V x 10µs pulse Table 9 Some requirements in MIL-STD-1541A. G. MIL-STD-1542B – space system facilitiesThis standard is intended for selected space system facilities. The requirements are applicable to allrelated facilities including, but not limited to, launch complexes, tracking stations, data processingrooms, satellite control centers, checkout stations, spacecraft or booster assembly buildings, andany associated stationary or mobile structures that house electrical and electronic equipment.MIL-STD-1542B addresses in detail the appropriate bonding, shielding, electrical power andground network for space system facilities. The facility ground network consists of the followingelectrically interconnected subsystems:www.intertek.com/emc/military-aerospace

a. The earth electrode subsystem. b. The lightning protection subsystem. c. The equipment fault protection subsystem. d. The signal reference (technical ground) subsystem.EMC performance for equipment installed in space system facilities is referenced to MIL-STD-461.COTS (commercial-off-the-shelf) equipment installed in these facilities shall also meet therequirements of MIL-STD-461.As with the other military EMC standards discussed here, MIL-STD-1542B requires electromagneticself-compatibility of equipment and systems. Clause 4.2 stipulates: Facility electrical and electronic subsystems and equipment shall be compatible with each other as well as with the technical equipment installed in the facility for support of space system operations. H. UK: DefStan documents Equipment procured for military purposes by the UK’s Ministry of Defence must meet their defence standards (DefStan). Non- military equipment must meet the essential requirements of the EMC Directive 2004/108/EC. Ministry of Defence EMC standards are listed in Table 10 below. reference title High Altitude Electromagnetic Pulse (HEMP) Protection for Ground Based Communication Facilities Def Stan 59-188-1 (2009) Performing Critical, Time-Urgent Missions - Part No: 1: Fixed Facilities. Def Stan 59-411-1 (2007) Electromagnetic Compatability - Part No: 1: Management & Planning Def Stan 59-411-2 (2007) Electromagnetic Compatibility - Part No: 2: The Electric, Magnetic and Electromagnetic Environment Def Stan 59-411-3 (2007) Electromagnetic Compatibility - Part No: 3: Test Methods and Limits for Equipment and Sub Systems Def Stan 59-411-4 (2007) Electromagnetic Compatibility - Part No: 4: Platform and System Tests and Trials Def Stan 59-411-5 (2007) Electromagnetic Compatibility - Part No: 5: Code of Practice for Tri-Service Design and Installation Table 10 UK Ministry of Defence EMC standardsCollectively the UK DefStan documents cover the same concerns as UK military standards.Specifically, DefStan 59-411-3 (Part 3) corresponds closely to MIL-STD-461F in methods, limits andfrequency ranges. For example, Magnetic emissions are measured at 70 cm in both standards, andhigh-frequency radiated emissions are measured at 1m in both standards. However there arestructural and content differences between the two standards: - Individual EMC tests in 59-411-3 are denoted DCS---, DCE---, DRE---, DRS--- where the “D” denotes “Defence” and is absent from -461 test references. - DefStan 59-411-3 uses susceptibility criteria A…D, which are familiar to users of commercial IEC and EU EMC standards. Default performance criteria are defined for each susceptibility test in terms of safety-critical or safety-related function, mission- critical function, or non-safety-critical or non-essential function.www.intertek.com/emc/military-aerospace

- “Man worn” and “man portable” categories and test requirements are specified in detail in DefStan 59-411-3. Testing for man-worn applications requires the use of a non-conductive dummy approximating the shape Figure 2 Man worn test configuration from DefStan 59-411-3, DCE02. I. NATO: STANAG documentsThe term “STANAG” stands for “Standardization Agreement” amongthe NATO member countries. There are literally hundreds of active agreements in place, usually drawing from one or more countries’ existing standards. Some of the STANAG agreements relating to EMC are summarized in Table 11 below. reference title STANAG 3516 Electromagnetic Interference and Test Methods for Aircraft STANAG 3614 Electromagnetic Compatibility (EMC) of Aircraft Systems STANAG 4234 Electromagnetic Radiation (Radio Frequency) - 200 kHz to 40 GHz Environment - Affecting the Design of Materiel for Use by NATO Forces STANAG 4239 Electrostatic Discharge, Munitions Test Procedures STANAG 4327 Lightning, Munition Assessment and Test Procedures STANAG 4370 Environmental testing STANAG 4416 Nuclear Electromagnetic Pulse Testing of Munitions Containing Electro-Explosive Devices STANAG 4437 Electromagnetic Compatibility Testing Procedure and Requirements for Naval Electrical and Electronic Equipment (Submarines)- Table 11 Some NATO STANAGs relating to EMC.www.intertek.com/emc/military-aerospace

Both environmental considerations and EMC are covered under STANAG 4370. It referencesseveral separate documents termed “Allied Environmental Conditions and Test Publication”(AECPT). We will explore the environmental aspects later, but we will look at EMC first.STANAG 4370 references AECPT-500 (Edition 3, 2009), “Electromagnetic Environmental EffectsTest and Verification.” AECPT-500 draws for its tests and methods both from MIL-STD-461 andDefStan 59-411, as shown in Table 12 below. Individual EMC tests in AECPT-500 are denotedNCS---, NCE---, NRE---, NRS--- where the “N” denotes “NATO” and is absent from -461 testreferences.Reference Description Test derived from NCE01 Conducted Emissions, Power Leads, 30 Hz to 10 kHz MIL-STD-461F NCE02 Conducted Emissions, Power Leads, 10 kHz to 10 MHz MIL-STD-461F NCE03 Conducted Emissions, Antenna Terminal, 10 kHz to 40 GHz MIL-STD-461F NCE04 Conducted Emissions, Exported Transients on Power Leads Def Stan 59-411 NCE05 Conducted Emissions, Power, Control & Signal Leads, 30 Hz to 150 MHz Def Stan 59-411 NCS01 Conducted Susceptibility, Power Leads, 30 Hz to 150 kHz MIL-STD-461F NCS02 Conducted Susceptibility, Control & Signal Leads, 20 Hz to 50 kHz Def Stan 59-411 NCS03 Conducted Susceptibility, Antenna Port, Intermodulation, 15 kHz to 10 GHz MIL-STD-461F Conducted Susceptibility, Antenna Port, Rejection of Undesired Signals, 30 Hz to 20 NCS04 MIL-STD-461F GHz NCS05 Conducted Susceptibility, Antenna Port, Cross Modulation, 30 Hz to 20 GHz MIL-STD-461F NCS06 Conducted Susceptibility, Structure Current, 60 Hz to 100 kHz MIL-STD-461F NCS07 Conducted Susceptibility, Bulk Cable Injection, 10 kHz to 200 MHz MIL-STD-461F NCS08 Conducted Susceptibility, Bulk Cable Injection, Impulse Excitation MIL-STD-461F Conducted Susceptibility, Damped Sinusoidal Transients, Cables and Power Leads, 10 NCS09 MIL-STD-461F kHz to 100 MHz NCS10 Conducted Susceptibility, Imported Lightning Transient (Aircraft/Weapons) Def Stan 59-411 NCS11 Conducted Susceptibility, Imported Low Frequency on Power Leads (Ships) Def Stan 59-411 NCS12 Conducted Susceptibility, Electrostatic Discharge Def Stan 59-411 NCS13 Conducted Susceptibility, Transient Power Leads MIL-STD-461F NRE01 Radiated Emissions, Magnetic Field, 30 Hz to 100 kHz MIL-STD-461F NRE02 Radiated Emissions, Electric Field, 10 kHz to 18 GHz MIL-STD-461F NRE03 Radiated Emissions, Antenna Spurious and Harmonic Outputs, 10 kHz to 40 GHz MIL-STD-461F NRS01 Radiated Susceptibility, Magnetic Field, 30 Hz to 100 kHz MIL-STD-461F MIL-STD-461F / Def Stan NRS02 Radiated Susceptibility, Electric Field, 50 kHz to 40 GHz 59-411 NRS03 Radiated Susceptibility, Transient Electromagnetic Field MIL-STD-461F NRS04 Radiated Susceptibility, Magnetic Field, (DC) Def Stan 59-411 Table 12 Cross-reference between NATO EMC test references, MIL-STD-461 and DefStan 59-411.AECPT-500 also contains a flow chart to guide the gap analysis between commercial and militaryEMC requirements, when COTS (commercial-off-the-shelf) or MOTS (military-off-the-shelf)acquisitions are being considered.www.intertek.com/emc/military-aerospace

Design for EMC complianceMilitary product development follows well-defined program steps. MIL-HDBK-237D defines thesesteps clearly – including tailoring of requirements - as well as providing useful information onpotentially applicable commercial standards plus standards from all branches of the US military,and NATO. An extensive list of acronyms is also included.Definition and refinement of the product EMC environment occurs during the course of programprogress. Initial EMC testing in the laboratory is only the first step toward full qualification. MIL-235B provides information on the likely levels of RF field exposure in various stages of deploymentto land-based and shipboard locations.Generally, EMC test requirements will have been fully defined before the product reaches the testlaboratory, although modules or subsystems may have been previously tested. The relevant partsof MIL-STD-461F (typically) will be stipulated, and it will be up to the manufacturer to have usedprudent design techniques to meet the designated requirements.As the EMC requirements in MIL-STD-461F are generally more stringent than commercialstandards, designing for successful compliance involves careful review of each level of productintegration. Can the designer support each of the design criteria in Data Item Description DI-EMCS-80199C, and summarized in this review? These criteria include PC layout, wiring, shielding,filtering and enclosure design. Designers familiar largely with commercial environments will needto review and enhance the use of EMC control techniques to meet military EMC requirements.Later qualification tests may require control enhancements.III. The Physical EnvironmentMilitary activities often take place inenvironmentally stressful circumstances – deserts,jungles, oceans, snowstorms and at high altitudes.The list of influences include: mechanical(vibration, impact, shock, acoustic noise); climatic(extremes of temperature, icing, winds, snow, dustand sand, rain, mist, fog); chemical and biological(mold, fungus, salt, acids, fluids); and abnormal(bullet, liquid fuel fire). In the face of thesechallenges the military equipment needs to remainfunctional and reliable.Commercially, the IEC 60068-x-y series wasdeveloped to include well over 50 specificenvironmental tests to account for real-worldphenomena. Still, these were not severe enough to simulate military conditions. A. USA: Supporting documentation - standardsThere are several US military environmental standards, each covering a different integration level,as indicated in Table 13.www.intertek.com/emc/military-aerospace

reference title MIL-STD-883G Test Method Standard - Microcircuits MIL-STD-202G Test Method Standard – Electronic and Electrical Component Parts MIL-STD-810G Test Method Standard - Environmental Engineering Considerations and Laboratory Tests Table 13 US military environmental standards. B. MIL-STD 883G – microcircuits MIL-STD-883G contains not only environmental tests, but mechanical and electrical tests as well. The amount of required environmental testing for microcircuits is extensive, as indicated in Table 14. Ref. description Ref. description 1001 Barometric pressure, reduced (altitude operation) 1016.1 Life/reliability characterization tests 1002 Immersion 1016.1 Life/reliability characterization tests 1003 Insulation resistance 1017.2 Neutron irradiation 1004.7 Moisture resistance 1018.5 Internal gas analysis Steady state life Ionizing radiation (total dose) test 1005.8 1019.7 procedure 1006 Intermittent life 1020.1 Dose rate induced latchup test procedure Agree life Dose rate upset testing of digital 1007 1021.2 microcircuits 1008.2 Stabilization bake 1022 Mosfet threshold voltage 1009.8 Salt atmosphere (corrosion) 1023.2 Dose rate response of linear microcircuits 1010.8 Temperature cycling 1030.2 Preseal burn-in 1011.9 Thermal shock 1031 Thin film corrosion test Thermal characteristics Package induced soft error test procedure 1012.1 1032.1 (due to alpha particles) 1013 Dew point 1033 Endurance life test 1014.12 Seal 1034.1 Die penetrant test (for plastic devices) 1015.9 Burn-in test Table 14 MIL-STD-883G environmental tests for microcircuits, by name of test.This standard contains a few ionizing radiation tests, appropriate owing to the known sensitivity ofmicrocircuits and the likelihood of exposure in high-altitude or non-conventional warfaresituations. Many of the tests are based on ASTM standards. C. MIL-STD-202G – electrical and electronic componentsThis standard establishes uniform methods for testing electronic and electricalcomponent parts, Including: basic environmental tests to determine resistance todamaging effects of natural elements as well as conditions surrounding militaryoperations; and physical and electrical tests. The term "component parts" in thisstandard includes such items as capacitors, resistors, switches, relays,transformers, inductors, and others. This standard is intended to apply only tosmall component parts, weighing up to 300 pounds, or having an rms testvoltage up to 50 kV.www.intertek.com/emc/military-aerospace

Table 15 below summarizes the environmental and physical tests required in MIL-STD-202G. Notethat, as the level of integration rises from microcircuits to larger components, the number ofphysical agents (sand, dust, physical shock, solvents) increases. reference description reference description Environmental tests Physical tests 101E Salt atmosphere (corrosion) (formerly 201A Vibration called salt spray) 102A Superseded by Method 107 202D Superseded by Method 213 103B Humidity (steady state) 203C Random drop 104A Immersion 204D Vibration, high frequency 105C Barometric pressure (reduced) 205E Superseded by Method 213 106G Moisture resistance 206 Life (rotational) 107G Thermal shock 207B High-impact shock 108A Life (at elevated ambient temperature) 208H Solderability 109C Explosion 209 Radiographic inspection 110A Sand and dust 210F Resistance to soldering heat 111A Flammability (external flame) 211A Terminal strength 112E Seal 212A Acceleration 213B Shock (specified pulse) 214A Random vibration 215K Resistance to solvents 216 Superseded by Method 210 217A Particle Impact Noise Detection (PIND) Table 15 Summary of environmental and physical test types in MIL-STD-202G. D. MIL-STD-810G – equipment, materiel, systemsThe MIL-STD-810 test series was created to allow generic laboratory environmental testing thatcould approximate battlefield conditions. Over time, the standard has focused more on shock andvibration tests that closely mirrored real-world operating environments.MIL-STD-810G not only consolidates the basic -810F with its three change notices to result in onecomprehensive document, but it also includes a number of corrections, significant changes, and additions to the comprehensive -810F, to include five new test methods, one of which (Method 526) was extracted from Method 516. Revision G implements Test Method 527 that requires multiple vibration exciters to perform simultaneous multi-axis shaking. This approach replaced the prior three tests: shaking a load first in its x axis, then its y axis, and finally in its z axis. The primary emphases are still the same (with the exception of Method 528): tailoring a materiel items environmental design and test limits to the conditions that the specific materiel will experience throughout its service life(handling, transport, storage, deployment), and establishing laboratory test methods that replicatethe effects of environments on materiel.www.intertek.com/emc/military-aerospace

At 804 pages, MIL-STD-810G is a massive document, but it is not an inflexible standard to befollowed to the letter. Rather, it recognizes that the environmental design and test tailoringprocess has expanded to involve a wide range of managerial and technical interests. Accordingly,it orients environmental design and test direction toward three basic types of users who havedistinctly different, although closely associated, interests: - program managers who ensure proposed concepts and systems are valid and functional in intended operational environments; - environmental engineering specialists (EES), who enter the acquisition process early to assist combat and materiel developer tailoring efforts by preparing life cycle environmental profiles and drafting tailored design criteria and test programs; - and the design, test, and evaluation community, whose analysts, engineers, and facility operators use tailored designs and tests to meet user needs.MIL-STD-810G is divided into three parts:Part One describes management, engineering, and technical roles in the environmental designand test tailoring process. It focuses on the process of tailoring materiel design and test criteria tothe specific environmental conditions a materiel item is likely to encounter during its service life. Aflow chart of the tailoring process is shown below, from MIL-STD-810G. 1) Conventional meteorological data are not collected with military hardware in mind. Great care must be taken to ensure that the meteorological data used are relevant to the specific materiel being tested. 2) In this context, a platform is any vehicle, surface, or medium that carries the materiel. Figure 2 Environmental test program tailoring process.Part Two contains environmental laboratory test methods to be applied according to the generaland specific test tailoring guidelines described in Part One. With the exception of Method 528,these methods are not to be called out in blanket fashion, nor applied as unalterable routines, butare to be selected and tailored to generate the most relevant test data possible.www.intertek.com/emc/military-aerospace

Part Three provides a wealth of climatic data and guidance assembled from several sources. Itprovides starting points for consideration of climatic conditions in the research, development, test,and evaluation (RDTE) of materiel and materials used throughout their life cycles in various climaticregions throughout the world.The program management and tailoring tasks specified in MIL-STD-810G are summarized in Table16 below.Task # acronym name purposeGuidance for Program Managers The MNS identifies environments that may constrain the operation or survivability of materiel, including natural, induced (e.g., temperature - MNS Mission Need Statement and vibration during transportation), and special operational threat environments (e.g., electronic emissions during battle) in which the mission is to be accomplished. Operational Requirements The ORD identifies materiel performance parameters that will meet the - ORD Document need described in the MNS. Program managers integrate environmental technical considerations System Engineering - SEMP (effects of various environments on system performance and reliability) Management Plan into the SEMP. The TEMP includes plans for testing in natural (field/fleet) environments, Test and Evaluation Master - TEMP simulated (laboratory) environments and virtual proving ground Plan (synthetic) environments.Environmental engineering tailoring tasks Environmental Engineering The EEMP is the basic management schedule used to integrate 401 EEMP Management Plan environmental effects considerations into the SEMP. The LCEP describes service-related events and environmental conditions Life Cycle Environmental 402 LCEP that materiel will experience from its release from manufacturing to the Profile end of its useful life. The OED task entails producing two documents. One is a plan for Operational Environment obtaining data that will serve as the basis for design and test criteria 403 OED Documentation development. The other is a report that contains those plans and the resulting data. The EICL contains a list of tailored issues and criteria, complete with Environmental Issues/Criteria appropriate criterion levels for the materiel being acquired. Also, it 404 EICL List includes rationale and assumptions for how environmental effects issues and criteria were derived. These detailed plans serve as the primary means for calling out specific Detailed Environmental Test 405 DETP laboratory and field tests, test sites, instrumentation, procedures, and Plan criterion levels for environmental tests. The ETR defines the test purpose, lists test issues/criteria, lists or describes test equipment/ facilities/instrumentation, explains the test 406 ETR Environmental Test Report design/set-up, contains detailed test data/logs, provides failure analyses, and interprets test results. The laboratory ETR is appropriate for design evaluation tests, operational worthiness tests, and qualification tests. Table 16 Program management and tailoring tasks described in MIL-STD-810G.Completion of Task 405, the Detailed Environmental Test Plan (DETP) leads to consideration of thetests contained in Part Two of MIL-STD-810G. The list of tests is summarized in Table 17 below.www.intertek.com/emc/military-aerospace

test # title test # title 500 Low Pressure (Altitude) 515 Acoustic Noise 501 High Temperature 516 Shock 502 Low Temperature 517 Pyroshock 503 Temperature Shock 518 Acidic Atmosphere 504 Contamination by Fluids 519 Gunfire Shock 505 Solar Radiation (Sunshine) 520 Temperature, Humidity, Vibration, and Altitude 506 Rain 521 Icing/Freezing Rain 507 Humidity 522 Ballistic Shock 508 Fungus 523 Vibro-Acoustic/Temperature 509 Salt Fog 524 Freeze-Thaw 510 Sand and Dust 525 Time Waveform Replication 511 Explosive Atmosphere 526 Rail Impact 512 Immersion 527 Multi-Exciter Testing Mechanical Vibrations Of Shipboard Materiel (Type 513 Acceleration 528 I – Environmental And Type II – Internally Excited) 514 Vibration Table 17 Environmental tests in MIL-STD-810G.Each test typically includes a number of sub-tests, selected for appropriateness in the tailoringprocess. For example, Test 500 (Low Pressure – Altitude) includes specifications for “rapiddecompression” as well as “explosive decompression.” Listing all of the key test parameters isbeyond the scope of this paper. The original document must be consulted for details. Figure 3 Map of world climate types from MIL-STD-810G, Part 3www.intertek.com/emc/military-aerospace

E. UK: DEFSTAN documentsThe UK Ministry of Defence Standard (DefStan) corresponding to MIL-STD-810G is DefStan 00-35Parts 1 – 6, ”Environmental Handbook for Defence Materiel.” Part 2 provides guidance on thederivation of environmental trials programs to be used in materiel type approval tests orassessments, similar to the tailoring described in MIL-STD-810G. It also presents a series ofidealized generic usage profiles to aid in the definition of user requirement documents and systemrequirement documents.Part 3, “Environmental Handbook for Defence Materiel - Part 3 - Environmental Test Methods”contains the test methods. Based to some extent on the IEC 60068 environmental standard series,this document contains environmental descriptions, a range of tests procedures and default testseverities representing conditions which may be encountered during the life of defense materiel.The test methods are grouped into sections relating to commonly encountered environments. Theuse of measured data for the generation of test severities is recommended if available, particularlyfor complex or safety critical items. The tests are applicable to materiel (both packaged andunpackaged) but some tests are also applicable to packages or materials. Tests may also beapplicable to subcomponents or parts thereof.DefStan 00-35 Part 3 divides its environmental test methods into four categories: - Mechanical - Climatic - Chemical and biological - Abnormal (accidental and hostile)The test references and descriptions under each category are listed in Tables 18 - 21 below. Test reference description Test M1 General Purpose Vibration test Test M2 Mulit-Exciter Vibration and Shock Test Test M3 Classical and Sine Waveform Shock Test M4 Drop, Topple and Roll Test Test M5 Impact (Vertical and Horizontal) Test Test M6 Operational Shock Simulation Test Test M7 Shock Testing for Warship Equipment and Armament Stores Test M8 Acoustic Noise Test Using a Reverberation Chamber Test M9 Acoustic Noise Test Using a Progressive Wave Tube Test M10 Combined Acoustic, Temperature and Vibration Test M11 Wheeled Vehicle Transportation Bounce Test Test M12 Bump Test Test M13 Steady State Acceleration Test Test M14 Test Track Trial Test M15 Lifting Test Test M16 Stacking Static Load Test Test M17 Bending Test Test M18 Racking Test Test M19 General Time History Replication Test Table 18 DefStan 0035 Part 3 mechanical tests.www.intertek.com/emc/military-aerospace

Test description reference Test CL1 Constant High Temperature - Low Humidity Test Test CL2 High Temperature, Low Humidity and Solar Heating Test Test CL3 Solar Radiation Test Test CL4 Constant Low Temperature Test Test CL5 Low Temperature Test Test CL6 High Temperature, Humidity and Solar Heating Diurnal Cycle Test Test CL7 Constant High Temperature - High Humidity Test Test CL8 Kinetic (Aerodynamic) Heating Test CL9 Rapid and Explosive Decompression Test CL10 Icing Test CL11 High Temperature - Low Pressure Test CL12 Low Temperature - Low Pressure Test Test CL13 Low Temperature - Low Pressure - High Humidity Test CL14 Thermal Shock and Rapid Rate of Change of Temperature Test CL15 Air Pressure (above Standard Atmospheric) Test CL16 High Winds Test CL17 Elevated Ground-Temperature/Humidity Diurnal Cycles Test CL18 Driving Snow Test CL19 Erosion and Structural Damage in Flight by Rain, Hail, Dust or Sand Test CL20 Rapid Change of Pressure Test CL21 Low Air Pressure and Air Transportation Tests Test CL22 Snow Load Test CL23 Impact Icing Test CL24 Freeze - Thaw Test CL25 Dust and Sand Test CL26 Mist, Fog and Low Cloud Test CL27 Driving Rain Test CL28 Dripproofness Test CL29 Immersion Test CL30 Sealing (Pressure Differential) Table 19 DefStan 0035 Part 3 climatic tests. Test reference description Test CN1 Mold Growth Test CN2 Salt (Corrosive) Atmospheres Test CN3 Acid Corrosion Test CN4 Contamination by Fluids Test CN5 Corrosion Test for Materiel Immersed in Salt Water Table 20 DefStan 0035 Part 3 chemical and biological tests.www.intertek.com/emc/military-aerospace

Test reference description Test FX1 Bullet Attack Test for Munitions Test FX2 Standard Liquid Fuel Fire Test FX3 Safety Impact Test for Munitions Test FX4 Slow Heating Tests for Munitions Test FX5 Sympathetic Reaction, Munition Test Table 21 DefStan 0035 Part 3 Abnormal (accidental and hostile) tests. F. NATO: STANAG documentsThe subject matter in US MIL-STD-810G is covered under the NATO Standardization AgreementSTANAG 4370, “Environmental Testing.” This agreement internally references other AlliedEnvironmental Conditions and Test Publications (AECTPs). The current AECTPs under STANAG4370 are: - AECTP-100 (Ed. 4) Environmental Guidelines for Defense Materiel - AECTP-200 (Ed. 4) Environmental Conditions - AECTP-230 (Ed. 1) Climatic Conditions - AECTP-240 (Ed. 1) Mechanical Conditions - AECTP-250 (Ed. 1) Electrical and Electromagnetic Environmental Conditions - AECTP-300 (Ed. 3) Climatic Environmental Tests - AECTP-400 (Ed. 3) Mechanical Environmental Tests - AECTP-500 (Ed. 3) Electromagnetic Environmental Effects Test and VerificationThe contents of AECTP-500 are comparable to MIL-STD-461F and DefStan 59-411, and theindividual test requirements are detailed in Table 12 above. AECTP-250 covers ambient conditionssuch as RF ambient, power quality and atmospheric electricity and lightning.Taken together, the AECTPs under STANAG 4370 generally cover the same environmental andmechanical tests as those in MIL-STD-810G or DefStan 00-35. The same emphasis on tailoring oftest requirements that exists in these standards is also given in the AECTPs.www.intertek.com/emc/military-aerospace

Design for Environmental ComplianceProduct environmental requirements are the result of well-defined program steps that includetailoring of these requirements to meet system performance goals and realistic materiel designs.MIL-STD-810G describes these processes in detail, as well as providing an extensive list of testmethods.The military environment includes mechanical, climatic and chemical abuse of the product.Compliant designs of electronic products begin with the suitable choice of PC components andmaterials to withstand the temperature extremes, conformal coatings to withstand moisture,chemicals and biological contaminants, and component mounting techniques to survive severeshock and vibration.Internal point-to-point wiring must similarly withstand temperature, moisture and chemical attack,and must be secured robustly to survive shock and vibration.An enclosure is the first line of defense against the onslaught of sun, rain, snow, conductive andcorrosive atmospheres and fluids. The enclosure materials and finishes must be suitably chosen.Controls, connectors and displays that penetrate the enclosure need adequate sealing or gasketing– again with appropriate materials. The enclosure can also contribute to EMC compliance, andthere may be design tradeoffs between conductive and non-conductive enclosures.Finally, the product’s mechanical construction and assembly methods must be able to withstandsevere temperature cycling, shock and vibration – requiring a serious review of fasteningtechniques and potential mechanical resonances in the structure.www.intertek.com/emc/military-aerospace

IV. SummaryMilitary EMC and environmental test standards and methods are well-documented in US andinternational jurisdictions. In some cases, EMC is regarded as a subset of environmentalconsiderations. While tailoring of test requirements is allowed under both EMC and otherenvironmental standards, it is actively encouraged in environmental standards.The equipment designer faces a daunting first-time task to collect, understand and act upon therelevant military standards for a particular product, system, or jurisdiction(s). This overview shouldhelp the designer to identify the necessary standards and scope of test requirements, so that thedesign can proceed on a firm basis.About IntertekAs a leading provider of quality safety solutions serving a wide range of industries around theworld, Intertek has the expertise, resources and global reach to support its customers through itsnetwork of more than 1,000 laboratories and offices – 39 specializing in EMC testing – in morethan 100 countries around the world.For more information regarding Intertek’s new developments, call 1-800-WORLDLAB or visit:www.intertek.comThis publication is copyright Intertek and may not be reproduced or transmitted in any form in whole or in part without the prior writtenpermission of Intertek. While due care has been taken during the preparation of this document, Intertek cannot be held responsible for theaccuracy of the information herein or for any consequence arising from it. Clients are encouraged to seek Intertek’s current advice on theirspecific needs before acting upon any of the content.www.intertek.com/emc/military-aerospace

Design practices for military emc and environmental compliance

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Design practices for military emc and environmental compliance — Document Transcript