Jamie Hamilton

Military Susceptibility Testing

Military Susceptibility Testing is performed to determine if a product can maintain normal operation when exposed to electrical, magnetic, and radio frequency, emissions and disturbances likely to be found in its intended environment.  In military applications, the density of equipment on a given platform and the levels of potential emissions and disturbances present create stringent requirements on product developers. 

To properly evaluate Equipment Under Test (EUT) the product developer must identify modes of operation most vulnerable to  these disturbances.  Simulation and monitoring equipment must be created that can exercise EUT in these modes and provide monitoring capable of capturing any abnormalities.  This equipment and its use must be documented in a test plans.  These test plans must also include criteria of acceptable operation and provide safety information such as emergency shut down procedures.

MIL-STD-461 Susceptibility Testing

MIL-STD-461 is an EMI/EMC standard for developmental test and evaluation.  This standard is broken out into nineteen various methods.  These methods include Radiated Emissions, Conducted Emissions, Radiated Susceptibility, and Conducted Susceptibility.

Military susceptibility testing includes radiated and conducted test methods.  These methods involve simulations of magnetic, radio frequency, Electrostatic Discharge (ESD), and Electromagnetic Pulse (EMP) sources of potential disturbance.  Susceptibility requirements are determined by type of equipment, type of platform the equipment is to be operational on, and location of the equipment on that platform. 

Susceptibility requirements for these methods generally exceed those found in commercial standards.  As an example, RS103, Radiated Susceptibility, Electric Field, specifies levels as high as 200 Volts/meter across a spectrum that may extend from 2 MHz to 40 GHz.

Test Plans and EMI/EMC Testing

Given the potential of equipment malfunction that could result in hazardous conditions and the very real possibility of damage to the equipment, properly executed testing is essential to verify a product meets requirements.  While MIL-STD-461 describes very concise instructions as to how a test procedure is to be conducted by test lab personnel this alone does not provide the information required about the equipment to be tested. 

As previously mentioned a test plan must be created to provide this critical data to the test lab and witnesses.  MIL-STD-461 sets very clear requirements for these test plans and their required information.

This information allows a lab to ascertain the specific chambers, equipment, and time that must be allotted for the procedures.  It establishes test parameters and severities for the test.  It provides description of the EUT, cabling, simulation, and monitoring equipment.  It also provides description of modes of operation and susceptibility criteria as it applies to the acceptable operation of the equipment.

CVG Strategy EZ-Test Plan Templates for MIL-STD-461

CVG Strategy offers EZ-Test Plan Templates for EMI/EMC testing for your military susceptibility testing.  These test plans compliant with MIL-STD-461 Electromagnetic Interference Test Procedures (EMITP) requirements per DI-EMCS-80201.  Test plans include Addendums for documentation of equipment specific information and test lab site and equipment descriptions. 

They also include instruction for test report construction that provides documentation of due diligence, information for post test analysis, and ensures repeatability of testing.

CVG Strategy Test and Evaluation Services

CVG Strategy test and evaluation experts can offer a wide array of services to assist your military susceptibility testing and other product test requirements.  These services include:

Pre-Test Product Evaluation

We offer Pre-test Product Evaluation to identify and mitigate potential system design vulnerabilities before you go to test.  This can streamline your test and evaluation by preventing costly redesign later in the program and lessen the requirements for retest.

Compliance by Analysis

In many cases products can be assessed to be compliant by analysis.  Compliance by Analysis methods can also be used to identify potential design deficiencies early in  product development, giving ample time for required modification.

Product Reliability

Product reliability testing assesses a product’s ability to perform all of its functions as designed throughout the entirety of its intended life.  This is essential for equipment that must operate in conditions of high environmental and dynamic stresses.  The goal of this testing is to identify potential reliability issues as early as possible so that designs can be modified prior to product release.

Product reliability testing is important in both commercial and defense product development.  Each market sector has unique approaches to achieving reliability.  For products designed for military applications MIL-STD-810 is a standard for developmental test and evaluation of a products reliability.

EMI/EMC Test Consulting

Military susceptibility testing presents challenging hurdles for product developers.  We can help by providing state of the art analysis of product at any time in the product test and evaluation cycle and provide design modifications that will provide solutions for emissions and susceptibility issues.

We can also provide susceptibility analysis that will help safeguard your product from faulty operation caused by radio frequency interference, electrical compatibility, and radio frequency communication coexistence issues.

 

Product Liability Issues Can be Prevented

Product Liability and Testing are areas that are of increased concern for product developers and manufacturers.  As products become more complex, properly designed test and evaluation programs must verify designs to prevent product liability issues that can greatly damage a company’s reputation.

Product Liability arises from incidents where a product’s performance departs from its intended design.  These incidents often involve serious injury or wrongful deaths.  These incidents can be caused by design defects, manufacturing defects, and failure to warn or marketing defects. 

Penalties imposed for cases of product liability vary from nation to nation and vary between states in the United States.  As a trend however, manufacturers are being held to more stringent standards around the world.

The Role of Test and Evaluation

Increased dependency on electronic products in every sector of our lives has created a greater potential for vulnerabilities that may cause serious injury or even death.  Product safety standards can and do address a good many of these vulnerabilities.  However, because a standard cannot address the wide range of environmental, electrical, and EMI/EMC effects that may be present in a product’s real world applications, it is often beneficial to conduct evaluations over and above those required for compliance to a given marketplace.

Environmental Causes of Product Failures

To assess testing requirements it can be helpful to conduct climatic and dynamic evaluations to examine the environmental stresses likely to occur in the lifetime of a product.  A useful tool for this analysis is a Life Cycle Environmental Profile (LCEP).  The LCEP is the method employed by MIL-STD-810 to identify stressors in all phases of a product lifetime, from leaving the shipping dock to final disposal. 

Although MIL-STD-810 is a DOD standard it is often used in commercial products where safety critical performance is a necessity.  Once an LCEP has been performed, realistic environmental issues and criteria can be established that will provide guidance for a test matrix that will be able to identify design deficiencies before production.

EMI/EMC and Electrical Product Failures

Because of the high volume of electronic devices in today’s world, the radio frequency environment is much denser across the spectrum than it ever has been.  This also causes abnormalities and disturbances on power distribution systems that these devices share.  Susceptibilities to electromagnetic interference are a major cause of operational anomalies. 

The causes of these anomalies can be very difficult to predict and reproduce in the lab.  Additionally, extreme care must be given to the design of monitoring equipment to catch intermittent failures in an EMI/EMC chamber while the equipment is under test.  Furthermore, selection of appropriate methodologies for evaluation can be challenging.  A susceptibility analysis can often assist in selection of relevant methods of evaluation.

CVG Strategy Can Help

CVG Strategy has decades of experience in product test and evaluation for equipment with safety critical requirements in a wide array of industries.  We have the expertise in both Environmental and EMI/EMC to provide thorough analysis of your product’s potential vulnerabilities.  We can then offer a wide array of services to verify a design before release to manufacture so that product liability concerns can be minimized.

COTS for Military Applications

The Defense Department is integrating more Commercial Off the Shelf (COTS) products for military applications including mission critical systems.  While this is a fantastic opportunity for businesses to gain access to a lucrative market, it also poses some serious challenges.

Once approved for a military application the manufacturer of the COTS must ensure that the products are designed to meet requirements for harsh environmental applications and stringent EMI/EMC limits.  This will often require extensive Developmental Test and Evaluation and probably a certain amount of design modification.

MIL-STD-810 Testing for COTS

MIL-STD-810 is the primary tool for Developmental Test and Evaluation for the environmental effects on military equipment.  This standard, currently in revision H, is comprised of twenty-nine methods for climatic and dynamic testing.  Climatic methods include High Temperature, Immersion, Fungus, Humidity, and Rain.  Dynamic methods include dozens of types of shock and vibration.

MIL-STD-810 does not rely on procedures with set parameters and severities.  Instead it requires an assessment of the critical environmental profiles likely to be encountered by the materiel in its life cycle.

This assessment involves a management and engineering process known as tailoring.  This is a critical decision-making process as the conditions a COTS in a military application would face on an aircraft would be entirely different than those in a shipboard application.  Added to this are consideration of all modes of transit likely to be encountered, both logistical and tactical.

MIL-STD-461 and Electrical Compatibility for Military Applications

MIL-STD-461 is the EMI/EMC standard for military components.  As such it often poses the greatest challenges to COTS transitioning into the military market.  Though requirements vary as determined by the intended platform (e.g. Army Ground, Aircraft Navy) they are generally more stringent for emissions and susceptibility than commercial items.

There are a number of standards that apply to electrical and electronic equipment for electrical compatibility.   The applicable standard is determined by the intended platform the equipment is to be installed in.

MIL-STD-1275 is used for 28 Volt DC powered items that are installed in military vehicles.  It includes methods to simulate the expected surges, ripples, limits, and starting disturbances found on these vehicles.

For equipment intended for use on aircraft, MIL-STD-704 is specified.  These methods include simulations of disturbances on various two phase, three phase, and DC power distribution networks found on military aircraft.

MIL-STD-1399 covers a wide range of power configurations found on shipboard power distribution systems.  These tests can be very involved and require significant time to complete.

CVG Strategy

CVG Strategy has expertise and experience in assisting companies adapt their products from the commercial marketplace to military applications.  Our experts can determine requirements and tailor environmental criteria to create effective Developmental Test and Evaluation programs.  Furthermore, our test and evaluation team can manage evaluation programs, write test plans, witness testing, and create test report summaries.  We have decades of experience in environmental and EMI/EMC testing in both commercial and military applications.

CVG Strategy is a consultancy offering coaching, mentoring, training and program development focused on areas including Business Process Improvement, ITAR and Export Compliance, Cyber Security and Quality Management Systems.

FCC Streamlines Approval Process

The FCC approval process has been streamlined for unintentional radiators.  Most electronic devices create radio frequency (RF) energy.  This energy can interfere with devices.  Intentional radiators are devices which communicate by way of radio frequencies (Bluetooth, Wi-Fi, radio).  Unintentional radiators create RF energy from their power supplies and digital components.  These devices are therefore less likely to interfere with the communications of other devices.

Because the previous requirements were confusing and time consuming the FCC’s streamlining of the approval process is a welcome relief to manufacturers of electronic products.

Supplier’s Declaration of Conformity (SDoC)

Previously the FCC required Verification and a Declaration of Conformity (DoC).  The new FCC approval process no longer requires Verification for unintentional radiators.  It now relies solely on the Supplier’s Declaration of Conformity (SDoC).  The SDoC is comprised of the following steps:

• Electromagnetic Compatibility (EMC) testing must be performed that conforms to FCC compliance standards.
• Preparation of a compliance information statement that includes product information, a list of a standards to which the product is compliant and the identification of a responsible party in the United States or its territories.
• The end user of the product must receive FCC approval compliance information in a paper or electronic user manual.
• The device should be labeled.  The label should uniquely identify a product name, identification number and/or description.
• A FCC label can be affixed, though not required.  An electronic label can be used for products with display capabilities.

 CVG Strategy

Our experts at CVG Strategy have extensive experience in the FCC approval process.  We have the experience in EMI/EMC to guide you in requirements for both commercial and military products.  CVG Strategy can provide pretest analysis, thereby reducing EMI emission test failures and their resultant delays. We also have expertise in Environmental testing and evaluation in a number of industries and products.  CVG Strategy specializes in Independent Developmental Testing and Evaluation including: Development of Life Cycle Environmental Profiles, Test Plans, Test Witnessing and Troubleshooting.

CVG Strategy is a consultancy offering coaching, mentoring, training and program development focused on areas including Business Process Improvement, ITAR and Export Compliance, Cyber Security and Quality Management Systems.