Military Product Testing – Verifying Reliability

military product testing

Military product testing is performed at various stages of a products development and service initiation.  The earliest phase of this testing is known as Developmental Test and Evaluation.  This phase is conducted by the product developer and includes a detailed regime of climatic, dynamic, EMI/EMC, and electrical compatibility test procedures.

The United States Department of Defense (DoD) has consistently had issues with the quality of testing provided by its vendors.  Defense systems that fail to meet their required level of reliability are less capable of fulfilling their intended missions and endanger the lives of personnel operating and depending on them.  Additionally these reliability issues can delay project implementation, involve costly redesign, and result in higher costs of operation.

As stated in Reliability Growth – Enhancing Defense System Reliability, issues exist with the quality of both operational and developmental test and evaluation currently being performed.  By adequately engaging in the preparation, execution, and analysis of developmental test and evaluation, designers of defense materiel can achieve higher levels of reliability, avoid redesign issues, and learn important lessons for future product design specifications.

military product testing

Elements of a Viable Product Test Program

Knowledge of Applicable Standards

For defense product developers a wide range of defense test standards are applicable.  These military standards include:

  • MIL-STD-810
  • MIL-STD-461
  • MIL-STD-1275
  • MIL-STD-1399-300
  • MIL-STD-704
  • MIL-STD-202
  • MIL-DTL-901

The test program manager should have a good working knowledge of these standards and understand their interrelation in terms of product development.  This knowledge should then be applied to the development of a test program that addresses perceived component vulnerabilities and prioritizes design verification testing of those concerns.  Ultimately, a test program must be created that addresses all requirements and returns important data for analysis.

Life Cycle Analysis

For environmental testing (climatic and dynamic) MIL-STD-810 “Environmental Engineering Considerations and Laboratory Tests” requires a thorough examination of the stresses likely to be encountered by the product during its service life, including logistical transit, tactical transit, maintenance, and operation.  This is accomplished by conducting a Life Cycle Environmental Profile (LCEP).  The LCEP along with customer requirements and any measured data provide data for the Environmental Issues/Criteria List.

From these documents a tailored list or Test and Evaluation Master Plan (TEMP) of required test methods with appropriate levels of stress can be created that will establish a basis for required testing.

Test Plan Preparation

Test plans must be developed that inform all personnel involved in testing, including the testing laboratory, of exactly how the test is to be performed, and what data is to be captured.  As most testing should be performed with the test item in an operational mode representative of expected service, the plan must include information as how these modes should be executed, monitored and recorded.  Additionally procedures for verifying the test items functionality before, during and post testing should be included.

Management of Complex Programs

Military product testing for military equipment involves a large number of mil-std tests.  Often these tests will be run concurrently.  Some tests can be performed in a few hours, others may require months for completion.  Staying abreast of test program activities, addressing failures, troubleshooting and providing root failure analysis are but a few of the responsibilities of a test program manager.

The manager must also coordinate all activities with product development engineers, laboratories, and shipping services.  Additionally interim and final reporting of the test program must be created.

CVG Strategy Product Test Consultants

CVG Strategy Test Management experts have extensive experience in military product testing as well as, commercial, aerospace, defense, and automotive product test and evaluation.  They have worked with numerous standards that apply to environmental and EMI/EMC testing.  They are adept at coordinating with product development teams to provide value added test programs that provide confidence in a products capabilities and reliability.

We can tailor a statement of work to include any number of tasks that might be required.  This can include:

  • Test Standards Technical Support for proposals and customer inquiries
  • Defining Test Requirements
  • Design of Simulation and Monitoring Equipment
  • Development of Required Test Fixtures
  • Development of Required Documentation
  • Test Scheduling
  • Onsite support
  • Laboratory Test Witnessing
  • Company representative and advocate at Test Lab
  • Subject Matter Expertise

Monitoring of Operational Testing and MIL-STD-810

Monitoring of Operational Testing

Monitoring of Operational Tests

Monitoring of operational tests and the recording of all critical performance parameters has become a requirement in MIL-STD-810H.

Operational testing has been a part of MIL-STD-810 since Revision C in 1975.  It refers to testing the item in a manner that represents service use as documented in the mission profile.  Successive revisions have placed more stringent requirements on this mode of testing.  Monitoring of operational tests is one such requirement. 

Requirements  as specified in Revision G change 1 Part 1, paragraph 5.10 reads as follows:

Performance check. Monitoring and recording of test item’s critical performance parameters is required before and after all tests. Monitoring of performance parameters is not required during non-operational tests such as storage and transportation. Monitoring of performance parameters during operational tests is strongly suggested.

Where cost concerns preclude monitoring during an operational test, consideration should be given to the consequences of undetected, intermittent failures.”

Revision H has changed the wording of the last two sentences of that paragraph to:

Monitoring and recording of the critical performance parameters during operational tests is required. If unable to monitor during operational tests, obtain test sponsor approval prior to the start of testing and document rationale in the test report.”

Monitoring of Operational Testing

Development of Monitoring and Simulation Equipment

Environmental testing has the capability of inducing intermittent failures in equipment.  Detection of these failures is critical in Developmental Testing and Evaluation to ensure a product’s capabilities during field testing and deployment.  These increased requirements call for a more diligent approach to the design and planning of monitoring equipment used in operational testing. 

Designing, building, and programming the required (off chamber) equipment requires time and resources.  Monitoring equipment should be capable of detecting recording and capturing intermittent failure conditions.  It should then notify test personnel of failures.  It should record all critical functions and exercise the Unit Under Test (UUT) to simulate in service operation. 

Additionally, it should be able to aid in the performance of functional and operational tests.  These tests are used to verify all modes of operation of the UUT before, during and after environmental tests.

Evolution of MIL-STD-810 Environmental Testing

Many issues have evolved during various revisions of MIL-STD-810.  A study of the history of these issues show a repeated effort by those writing the standard to stress areas where materiel developers have fallen short in developmental test and evaluation.  This has been the case with test parameter tailoring, power requirements, and yes, the methods utilized in operational testing.

There are numerous issues that can cause intermittent issues in electrical and electronic equipment: 

  • Tolerance stacking of components can often lead to intermittent failures during temperature testing. 
  • Humidity can cause intermittent reductions in the electrical isolation of signals. 
  • Dynamic testing, especially where higher frequencies are present, i.e. Pyroshock testing, can cause piezoelectric effects. 

These intermittent failures can lead to unexpected behaviors from equipment that can result in a number of safety related issues especially when the equipment being tested is mission critical.  The increased requirements in MIL-STD-810 no doubt can be traced to issues encountered during operational testing or during service.

In essence, a “green light” on the UUT is no longer a suitable solution, if indeed it ever was.  Properly designed equipment is required monitoring operational tests during tests. It is impossible for a human to monitor a test of long duration or perceive short intermittent failures.

Other Requirements for Monitoring and Simulation Equipment

Such monitoring equipment is also useful in EMI/EMC testing for detecting susceptibility issues.  It can also exercise the equipment under test to provide representative operation necessary for adequate evaluation of equipment emissions.  Operational testing is a requirement for most EMI/EMC testing. 

It is definitely a requirement for MIL-STD-461 testing.  Operation of equipment in standard modes is required for modes of testing in this standard including conducted emissions, radiated emissions, conducted susceptibility, and radiated susceptibility. 

For emissions testing, exercising the Equipment Under Test (EUT) exercises it to create a nominally characteristic level of electromagnetic behavior.  During susceptibility testing however, great care must be taken to monitor the EUT for operational failures caused by the presence of electromagnetic fields and electrostatic discharges.

The same holds true for electrical compatibility testing.  This testing includes standards such as MIL-STD-704, MIL-STD-1275, and MIL-STD-1399-300B parts 1 and 2.

CVG Strategy Product Test and Evaluation Experts

Our experts at CVG Strategy have extensive experience in Environmental and EMI/EMC testing and evaluation.  We have expertise in a number of industries and products, both military and commercial.  CVG Strategy specializes in Independent Developmental Testing and Evaluation including: Development of Life Cycle Environmental Profiles, Test Plans, Test Program Management, and Test Witnessing.

CVG Strategy also offers MIL-STD-810 Webinars that stress methods for employing this important test standard to get the most out of your test and evaluation program.

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

Preparing for EMI Testing – Important Considerations

Preparing for EMI Testing
Preparing for EMI Testing

Preparing for EMI Testing can save time and money. Most EMI tests do not provide the news we want to hear on the first trip, therefore preparing to go the lab then is a task that should be thought out. 

Emissions and immunity testing is an important part of your product development.  Successful testing can provide compliance to relevant international standards and allow you to get your product to market.  It can also ensure your product is not susceptible to interference that can cause damage, injury, and product recalls.

Pre Compliance Testing

There are many EMC pre-compliance tools available to product developers today.  These can provide screening to prevent trips to a lab when a product would clearly fail.  They can also aid in troubleshooting to evaluate required design modifications.  While these tools can definitely provide an edge for emissions testing they are not as useful for immunity, susceptibility, and power compatibility testing.

Pre test Product Evaluation and Susceptibility Analysis

EMI/EMC expertise can help solve difficult EMI/EMC issues.  Our EMI/EMC experts have decades of experience and help provide analysis and design modifications to address design deficiencies.  We can also provide a susceptibility analysis for safety critical devices.  This type of analysis is now a requirement for medical devices that must pass coexistence testing.

Equipment to be Tested

We can start by taking a close look at what the product item we are sending.  Is it truly representative of the finished product?  Will it be running with representative firmware and software?  Are the cables representative of the finished product?  All of these factors will greatly effect the veracity and data provided from the test. 

Often early manufactured samples of a product will have coatings where they shouldn’t be.  Check your test item for unwanted paint or powder coat that could interfere with grounding of enclosures and connectors.  Removing paint at the lab is time consuming and time goes by very quickly at the lab.

Have EMI/EMC Test Plans

Another way to prepare for EMI testing is to know what tests are required and understand which sequence of tests are to be run.  Write EMI test plans to communicate product specific information among the design team, the test lab, and the customer. These information can include pass/fail criteria for modes of operation to be tested in immunity testing.

In the defense industry, a test plan can be a contract requirement.  Aside from documentation of desired procedures the writing of the procedure will reinforce and deepen the Test Witnesses understanding of test details.

The Kitchen Sink

When preparing for EMI testing make sure you have appropriate support hardware to exercise the equipment under test so that operational modes are representative of the product in its intended usage.

Bring extras of everything.  If you have had enough forethought to provide extra component places on printed circuit boards near I/O connectors for ferrites and capacitors bring plenty of different values to play with if required.  Bringing your own soldering equipment can be useful as well.  Always bring multiple samples of the equipment to be tested and extra cables.

Most importantly, bring an appropriate mind set to your EMI test.  Everybody wants to bring home a win, but bringing back important data from a test failure is invaluable.  Remain flexible and be prepared to change course so that you can best isolate and analyze the causes of failure.  This will involve cooperation with lab personnel so developing and maintaining a good working relationship with these people is very important.

CVG Strategy Experts

Our experts at CVG Strategy have extensive experience in Environmental/Dynamic and EMI/EMC testing for a number of industries and products, both military and commercial.  CVG Strategy specializes in Independent Developmental Testing and Evaluation including development of Test Plans, Test Procedures, 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.  For any additional questions, please contact us now!

EMC Testing and Risk Management

EMC Testing and Risk Management
EMC Testing and Risk Management

It wasn’t long ago that EMC Testing and Risk Management wouldn’t have appeared in the same sentence.  Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC) testing has normally been performed to meet the criterion established for a desired label.  Once compliance testing has been passed, it’s off to market.

Medical Equipment Safety Concerns

A modern medical facility is packed with electronic equipment.  Much of this equipment is directly involved with safety critical tasks involving life support, monitoring patient vital signs, and alerting personnel of critical situations.  Other equipment in the environment such as cell phones, microwave ovens, and radio devices can interfere with the normal function of safety critical equipment resulting in unknown or behaviors. 

A list of EMI disturbances in medical devices was released in Interference Technology 2020 Medical EMC Guide.  They include:

  • An ambulance radio interfering with a monitor/defibrillator resulting in death.
  • Failure of renal dialysis equipment due to power input susceptibility.
  • Pacemaker compatibility issues when exposed to 13.56 MHz RFID readers.

Risk Management and IEC 60601-1-2

As a result of incidents of medical equipment susceptibility standard such as IEC 60601-1-2 now require a risk assessment be performed before testing to determine immunity test levels and pass fail criteria.  This analysis must be conducted by the manufacturer.  It should define the essential performance each essential function of the device to be tested against the factors likely to be encountered in the intended environment.  These factors include radiated energy sources, conducted sources, electrostatic discharge, and power fluctuations and disturbances.

After this assessment is performed a list of relevant immunity test methods can be selected at realistic levels can be documented in a test plan.  This test plan, again, is the responsibility of the manufacturer to create.

EMI Risks in Other Applications

Electronics are everywhere.  When they are capable of producing safety risks, EMI testing beyond demonstration of compliance is a consideration.  The braking problems that plagued Toyota in 2010 were caused from EMI.  As vehicles become more densely populated with electronic devices the ability of all devices to coexist becomes more questionable.  Additionally portable devices such as cell phones contribute to a more complex radio environment.

EMI Standard Development

As mentioned at the beginning of this article EMC testing does not typically include risk management.  Most testing is performed to exacting standards that set a fixed level for compliance. 

Because standards lag behind the technologies they seek to regulate it is likely to be sometime until risk assessment is fully embraced by these standards.  In time, however, EMC will have to be embraced as an essential part of quality management to ensure the basic safety of the devices we rely on everyday.

CVG Strategy EMI Consultants

CVG Strategy EMI/EMC consultants can provide susceptibility analysis and recommend appropriate test methodologies for verification a product’s ability to perform as specified in today’s congested spectrum.

 

 

 

 

Health Effects of RF Energy and Microwaves

Health Effects of RF Energy
Health Effects of RF Energy

The health effects of RF energy have been a concern voiced by many in recent years.  Questions have been raised about the use of cell phones and the introduction of 5G.  Now the military has raised concerns about the cognitive effects of radio frequency energy on pilots.

U.S. Military Concerns About RF Noise Exposure

A recent article in Military & Aerospace Electronics reported that the U.S. Defense Advanced Research Projects Agency (DARPA) is seeking help to determine if RF emissions effect human cognitive processes.   They are also, if the study proves positive, looking for ways to mitigate those effects. 

This follows reports from pilots of minor cognitive performance issues during flight.  Because a cockpit flooded with RF noise, many experts believe this energy may cause spatial disorientation, memory lapses, misprioritization, and complacency.  This is a very real concern because spatial disorientation is a leading cause of accidents resulting in loss of life.

Findings from this study should have an impact on commercial applications, where RF environments are becoming increasingly active.  This would include commercial pilots and perhaps even motor vehicles.

Previous Concerns About the Health Effects of RF Energy

Ionizing Radiation

Most concerns about health and electromagnetic energy have focused on ionizing radiation.  Ionizing radiation has enough renergy to break bonds between molecules and ionize atoms.  This type of activity requires large amounts of radiant energy. 

Typical sources would include X-rays, cosmic rays, and radon.  Exposure to these sources of radiation can result in cancer risks.

Non-Ionizing Radiation

Non-Ionizing radiation sources of radiation include radar, microwave ovens, cell phones, and the electronic devices that we encounter in our daily lives.  While this type of radiation cannot directly damage DNA, there have been concerns about RF absorption causing heat in cells and tissues.  Studies conducted by the World Health Organization (WHO) have not been conclusive.  While there have been some evidence of increased gliomas in heavy users, there was inadequate evidence to draw conclusion about other types of cancer.

Low Frequency Electromagnetic Fields (EMF)

Low frequency EMF is generated from source such as power lines.  There has been some evidence suggesting a link between exposure and childhood leukemia. While evidence suggests that exposure is possibly carcinogenic, again no conclusive evidence was found. 

Guidelines on the Health Effects of RF Energy

Exposure standards and guidelines have been developed by various countries around the world.  While the U.S. does not currently have a standard for exposure limits, the Federal Communications Commission (FCC) has adopted and used safety guidelines for evaluating RF exposure.  the Occupational Safety and Health Administration (OSHA) did release a standard but later deemed it to be advisory.  Perhaps the most substantial and used guidelines are those put forth by the American National Standards Institute (ANSI) and the Institute of Electrical and Electronics Engineers (IEEE).

Where are We Headed?

Devices that create radio frequency energy are proliferating at an ever accelerating rate.  Radar, lidar, and Internet of Things, are creating a very dense radio energy environment.  So much so that devices are having coexistence performance issues. 

We are truly treading into uncharted territory.  While extant focuses on health effects of RF have dealt with physical effects, the effects of RF on the electrical chemical activities of neurological processes have not been explored.

New findings may well lead to required changes in the way we interact with devices in our lives.  If electromagnetic emissions do indeed effect cognitive processes then new standards for safety will need to be created.  As a result, product design constraints and changes in required test and evaluation for product certifications will arise.  This could very well be a subject to monitor closely.

Components for Hypersonic Applications – Considerations

Components for Hypersonic Applications
Components for Hypersonic Applications

Components for hypersonic applications are required for an increasing number of Department of Defense (DoD) projects.  These components and assemblies must be able to function under very demanding circumstances.  Typical stresses include altitudes exceeding 100,000 feet, rapid temperature changes, vibration, pyroshock, and acceleration.  This provides unique challenges to designers and those involved in test and evaluation.

Design Challenges for Components for Hypersonic Applications

Current defense designs can involve flight speeds of anywhere from Mach 5 (3,800 mph) to Mach 10 (7,600 mph).  Future designs may reach speeds near Mach 30 (23,000 mph).  This produces high levels of vibration, shock, and heat. 

These stresses require that each device for a printed circuit board must be carefully selected.  Furthermore, care must be taken in the design of circuit boards to avoid failures at connection points.  Care must also be taken to prevent resonances that can destroy components or cause intermittent failures due to to piezoelectric effects.  

These requirements for rugged designs are driving development of new cooling, adhesive, and dampening solutions.  The outcomes will likely result in revolutionary technologies.

Hypersonic Test and Evaluation Requirements

Often testing for these designs must be performed for both qualification and acceptance of system components.  This requires vast resources of test equipment and test facility time. Additionally, because parameters are extreme, equipment capable of performing a test can be difficult to find.

To complicate matters, test values can often fall outside the capabilities of test equipment at both ends of the spectrum.  This can be the case with pyroshock where a value is too large for an electodynamic shaker systems but beyond the lower limits of a resonant beam device.  Pyroshock is a critical test because it involves dynamic forces with a frequency range extending to 10,000 Hz. 

CVG Strategy Product Testing Services

CVG Strategy provides program management for defense and commercial test and evaluation.  We can work with multiple test facilities to coordinate testing on high end test equipment required for analysis where reliability is essential.  Our experts can ensure that testing is performed as required and that essential data is recorded.  Contact us for answers and solutions to your test and evaluation challenges.

Understanding MIL STD 810 and How to Use It

Understanding MIL STD 810
Understanding MIL STD 810

Understanding MIL STD 810 is essential for proper developmental evaluation of the environmental effects on equipment.  CVG Strategy has been helping our customers use this valuable standard to create test programs for over a decade.  In this time we have seen a number of commonly held misconceptions about the standard and how to use it. 

What is MIL STD 810?

MIL STD 810 is used to evaluate the influences of environmental effects on equipment during all phases of its life cycle.  It includes 29 methods for analysis of those effects.  These methods include climatic (temperature, humidity, solar, etc.) and dynamic (e.g. vibration, shock, pyroshock).  With the exception of one of these methods, there are no established severities or pass/fail criteria.  Why?  Because these variables are dependent on the type of equipment being tested and where it is to be used.  Using high temperature as an example; the appropriate high temperature for equipment intended for a vehicle crew compartment is very different than one for an engine compartment or the exterior of a supersonic aircraft.

How to Use the Standard

The secret to using the MIL STD 810 is in the seldom read Part 1 of the standard.  Part 1 establishes a process for evaluating the relevant environmental stressors likely to be encountered in the product’s life time.  This includes storage, transport, and operational configurations.  It provides a tailoring process to create realistic design parameters and test methods.

One tool that this tailoring process entails is the creation of a Life Cycle Environmental Profile (LCEP).  This process identifies all the environmental stresses from shipping dock to end of life.  Metrics can then be fed into an Environmental Issues/Criteria List (EICL) that can be used as design and test parameters.  When measured data for a given stress is known, that data should be used.  When a value is not known, guidance is provided in the standard for realistic evaluation based on climatic and measured dynamic variables.

Developing a Plan

The first task is to create a Test and Evaluation Master Plan (TEMP) that outlines all the testing to be performed.  This can include multiple tests for each method.  Using high temperature again as an example,  it is often prudent to perform testing for transport, storage and operational tests, each with its specific values and temperature profiles.  Each of these tests should have a Detailed Environmental Test Plan (DETP) to exactly specify how the test is to be conducted.  This description should include required operational tests, data to be recorded, and pass/fail criteria.  People often ask test labs to create test plans.  This is not the best solution as the lab does not have a thorough understanding of the equipment and cannot perform the LCEP and EICL steps of the tailoring process.

Operational Testing and MIL STD 810

MIL STD 810 has, with increasing intensity, stressed the importance of operational testing.  Climatic and dynamic stressors can often cause intermittent failures of equipment.  It is therefore of great importance to create operational testing that exercises all modes of operation.  It is also important to create equipment that can monitor the equipment and capture those failures.  This process is one that is often overlooked.  As a result, testing performed does not provide substantive evaluation of the test item.

CVG Strategy Can Help

We provide a variety of services to help you garner the most from your test and evaluation program.  CVG Strategy offers webinars to increase your understanding of MIL STD 810.  These courses stress the importance of the tailoring process and empower you to create appropriate test programs.  We can create LCEPs and EICLs that reflect your product’s needs.  We provide EZ-Test Plan Templates for product segments such as Ground Mobile, Shipboard Controlled, and Aircraft Military.  Our test and evaluation experts can also create custom test plans for your product requirements.

To assist your product development during this Covid-19 crisis we offer test program management and test program witnessing.  This frees your team from travel requirements and ensures that testing is performed as specified.  CVG Strategy is partnered with labs in the Florida area to help you. 

Contact Us today to see how we can help you.

 

Witnessing EMI Testing Properly Adds Value

Witnessing EMI Testing
Witnessing EMI Testing

Witnessing EMI/EMC testing is a complex task.  Conducting this task properly can add value to your product development efforts.  More often than not products fail their initial testing.  Because of this, iterations of redesign and retest are required.  This can result in budgetary and scheduling issues for your design team and delay getting your product to market.

What is EMI/EMC Testing?

Let’s start by defining what testing is.  The word test has many definitions.  The definition critical for our subject is “a procedure for critical evaluation“.  There is significantly more going on than the pass/fail exams we took in college.  This process verifies that the product will meet design specification when operated in its intended environment and validate that it meets or exceeds customer requirements. 

When products experience issues in the field they can interfere with other equipment in their environment.  They can also be susceptible to radio frequencies that result in unexpected behaviors of the product.  These issues can result in property damage, injury, and death.  They can also result in product recalls, product liability cases, and fines.  Therefore properly conducted testing is of great importance.

Have a Plan – A Test Plan

The first step is to understand what testing is to be accomplished.  This will require reading and comprehending the standard and its requirements.  Once that has been done creating a test plan is essential.  This is because it is important to clearly communicate to lab personnel important information that is specific to your equipment.  This would include:

Testing to be Performed

This not only would include what testing is to be performed but document required pass/fail criteria.  This is because many standards will have different requirements for various classifications of equipment. 

Description of Equipment to be Tested

This should include a general description including model, serial number, and version numbers for hardware and software.  It should also include power requirements and overall size of the equipment.

Modes of Operation

This section should define all operational modes of the equipment, control settings, required interconnections.  It should also include any grounding or load requirements.

Performance Checks

Remember that we are trying to verify and validate the performance of the product.  Testing the equipment in an idle mode will not accomplish this goal.  Therefore it is important to provide simulation equipment to exercise the test item during both emissions and susceptibility procedures.

Susceptibility Criteria

It is important to define what your equipment’s acceptable level of operation when conducting susceptibility testing.  Often requirements for classes of equipment are established in the test standard.  This will inform the lab what the pass/fail criteria for the test will be.

Electrostatic Discharge Schedules

It is a good idea to document test points for Electrostatic Discharge (ESD) testing.  The documentation should include points where likely discharges from human contact would occur.  This documentation instructs the lab personnel to conduct a test that returns valid data.

Witnessing EMI Testing – Do the Work

Sitting in the waiting room of a lab plinking on a laptop is not providing any value to test activities.  A test witness should go to the lab prepared to work.  Communicate with the lab personnel what is to be done and make sure they are clear about the details.  Set up the test equipment and ensure it is operating correctly.  Place the equipment into a required mode of operation and check to see that simulation equipment, monitoring equipment and loads are behaving properly.  It is important to assist in monitoring the test item to capture any intermittent failures when performing susceptibility testing.

Data Gathering and Troubleshooting

The real challenge when witnessing EMI/EMC testing is when a test fails.  Time management is critical.  Selecting the best avenue for isolating and analyzing the cause of the failure can best utilize that time.  While you may not be able to “solve” the problem at the lab, you can identify causes of the failure.  You can also identify mitigation techniques that should be considered for design modification.  All of this activity should be documented and included in a final report.

CVG Strategy

It can be a challenge to perform witnessing of EMI/EMC testing in the new reality of Covid-19.  Travel of essential personnel to test facilities is often not an option.  CVG Strategy test and evaluation consultants are ready to help.  We are partnered with local labs to provide test program management and test witnessing services.  We offer a variety of test documentation products including our EZ-Test Plan Templates.

Our subject matter experts have decades of experience in aerospace, automotive, defense, and commercial applications.  They can help you with design issues by performing product evaluations and susceptibility analysis.  Contact Us today to see how we can help.

Tech Standard Development Open to U.S. Companies

Tech Standard Development Open
Tech Standard Development Open

The US Department of Commerce has announced that tech standard development is open to participation by U.S. companies.  This new rule is designed to allow U.S. technology companies to influence the future of cutting edge technologies.

The Role of Standards in Technology

Standards are created to establish minimal criteria for functionality, interoperability, and safety.  They also establish methods of test and evaluation to ensure those criteria are met by products.  Because these standards effect the manner in which products are specified, it is important that U.S national security and foreign policy interests are represented in their formation.

Important Considerations for Future Standards

Because technology is controlling more and more critical functions, it is important that it functions safely and reliably.  This is especially this case for technologies like autonomous vehicles, and medical devices.  The ability of devices to not interfere with each other and coexist operationally is of increasing concern.  Standards must be created and evolve to rapidly developing technologies and airways that are becoming busier with wireless communication.

The Importance of U.S. Involvement

Making tech standard development open to U.S. tech firms allows major technology developers to shape the industry based on expectations of future product capabilities.  U.S. product standards are often accepted as a baseline for the creation of international standards. 

Department of Commerce Secretary Wilbur Ross stated “The United States will not cede leadership in global innovation. This action recognizes the importance of harnessing American ingenuity to advance and protect our economic and national security.  The Department is committed to protecting U.S. national security and foreign policy interests by encouraging U.S. industry to fully engage and advocate for U.S. technologies to become international standards.”

Reasons for Concern

Huawei, a Chinese technology company, has been at legal loggerheads with the United States.  It has also been very active in the development of various international standards.  This action is meant to ensure Huawei’s placement on the Entity List in May 2019 does not prevent American companies from contributing to standards that will shape the future of important technology.

CVG Strategy

CVG Strategy offers consultant services for export compliance and ITAR.  We also offer a variety of services for product test and evaluation to commercial and defense standards.  We have expertise in environmental and EMI/EMC standards provide product test program management to assist your product development program during the Covid-19 pandemic.  Contact us today to see how we can help.

Product Test Management Services Help During Pandemic

Product Test Management Services
Product Test Management Services

CVG Strategy Offers Product Test Management Services

Product Test Management Services can assist in keeping product development schedules on track during the Covid-19 pandemic.  Many product developers are already behind schedule due to lock downs.  Sending engineering staff on travels to laboratory may not be a desirable option at this time.  CVG Strategy can help by providing a number of services to ensure that your product test and evaluation are performed properly. 

Solutions for Product Testing

The CVG Strategy test and evaluation team have decades of experience in product test management.  We can provide everything from defining test requirements to creating final test report summaries.  We have expertise in climatic, dynamic, ingress, product safety, EMI/EMC, and electrical test methods.  Services we provide include:

  • Test Standard Research
  • Life Cycle Environmental Profile for Reliability Analysis
  • Susceptibility Analysis
  • Test Requirement Analysis
  • Design of Required Simulation and Monitoring Equipment
  • Vibration Test Fixture Design
  • Test Plan Development
  • Test Scheduling
  • On Site Test Witnessing
  • Subject Matter Expertise for Pre and Post Test Evaluation

Third Party Advocate for Your Product

Product Test Laboratories, by definition, are limited in their ability to act as an advocate for your product.  Additionally, because of their customer load, they are unable to provide in depth attention to details such as product modes of operation.  Testing is complicated, expensive, and important for product verification and validation.  Attention to details can catch intermittent susceptibilities and vulnerabilities that can lead to product recalls and liabilities.  They can also prevent under or over test conditions that would invalidate test results. 

The collection of pertinent data is very important in testing.  It is essential for post test analysis of failures.  It is also necessary for test replication where sensor placements and device under test set up are critical.  CVG Strategy can provide through all of its services an attention to detail that is borne out of experience in hundreds of test programs.

Sectors of Product Test Management Service Experience

CVG Strategy has experience in the test and evaluation of many product sectors.  These include:

  • Defense
  • Commercial
  • Automotive
  • Aerospace
  • Ingress Protection
  • HALT and HASS

We can provide Subject Matter Expertise to assist in design analysis and troubleshooting for these sectors that can prevent recurrent test failures.

See How We Can Help

Contact Us today to see how we can help keep your product development on schedule.  We also offer EZ-Test Plan Templates for a number of test standards. 

 

Continuous Improvement and Organizational Development

Continuous Improvement and Organizational Development
Continuous Improvement and Organizational Development

What is Continuous Improvement?

Continuous Improvement and Organizational Development are valuable tools in a Quality Management System (QMS).  For improvement to occur it is essential that each important process in an organization be identified and analyzed.  Once identified and documented, these processes can be regularly reviewed to access effectiveness by applying improvement based on metrics.  It is important to realize that everything that happens in a business is a process and should be evaluated for inclusion into a QMS.  This is because there are no activities that can not be made more effective.  The benefits of this effectiveness can include increased product quality, enhanced customer satisfaction, reduction of costs, and employee satisfaction.

Types of Continuous Improvement

Basically there are two types of continuous improvement, incremental and breakthrough.  It all boils down to the size of the steps. Big steps can be more costly and involve a greater risk.  Therefore they are often reserved for cases where radical change is required.  Incremental improvement is taken in small steps an can be easily assessed for effectiveness.  Thereby allowing for more immediate adjustment of changes.

Establishing Paths for Feedback

Organizational feedback is very similar to feedback in mechanical systems.  The famous Scottish inventor James Watt pioneered early feedback mechanisms in the 1700’s.  One of his most important inventions was the centrifugal governor.  This mechanism automatically regulated the speed of a steam engine by supplying continuous feedback to a controller.  This mechanism paved the way for industrial automation and increased safety by removing the need for human intervention in a continuous process.

In a business setting, every stakeholder in a process is a source of feedback.  For effective use of the feedback all pertinent information must be assessed.  It must then be filtered in such a way as to remove statistical noise and then intelligently applied to inputs.  When applied, outputs can (results) be monitored as feedback to supply a control system into the process to provide continuous improvement.

Statue of James Watt, engineer and inventor, 1736 – 1819

Using Metrics as Feedback

Businesses today exist in a metrics rich environment.  A wealth of data is available for sales, costs, defective product, customer satisfaction, and employee process suggestions.  Looking into all data available in a process on a regular basis can provide more granular and intelligent findings.  These findings can be used to identify trends and point out potential issues before they become critical.  This is important because variances in business performance can occur for any number of reasons.  Understanding how all processes are effected by change can provide dynamic responses for continuous improvement and provide a smoother overall performance.

CVG Strategy

CVG Strategy quality experts understand continuous improvement and organizational development and how to set up management systems that can provide vital feedback as a business changes through all phases of development.   Contact Us with your questions to see how we can help.

Test and Evaluation for Robustness

test and evaluation for robustness
test and evaluation for robustness

Test and Evaluation for Robustness

Test and Evaluation for robustness of a product is an involved process.  For electrical and electronic equipment an evolution of design engineering evaluation has been required to meet acceptable failure rates for fielded product.  Instituting these test methodologies requires looking beyond a test to pass approach.

Robustness in Military Applications

In the military this requirement was apparent following World War II where new materiel had often failed to meet performance criteria when introduced to its operational environment.  This led to the creation of AAF Specification 41065 in 1945.  This specification was comprised of ten methods for developmental product evaluation with preset parameters.  This standard later became MIL-STD-810 Environmental Engineering Considerations and Laboratory Tests

As this standard evolved, it became more and more apparent to those writing it the limitations of a cookie cutter approach.  Environmental issues are far too complicated and nuanced to be easily defined in a manner that is appropriate for all applications.   Because of this, every revision of the standard has increasingly stressed the need for tailoring tests to meet the anticipated environmental stresses in the lifetime of the product.  

Because industry largely ignored the requirements for tailoring, a tailoring process was created in revision G in 2008.  Despite this though, developmental test and evaluation of products has often not been adequately performed.  This has led to costly redesigns in operational testing phases and caused delays in final systems.

Robustness in Automotive Applications

As electronics were first introduced in automobiles failure rates were excessive.  These failures were caused by climatic, mechanical, chemical, electrical, and electromagnetic stresses in vehicle applications.  As the industry moved towards longer warrantied products, emphasis shifted from the detection of failures at the end of the development process to prevention of failures throughout the full life cycle. 

This prevention requires designing for ruggedness at concept development with a Zero-Defect Strategy.  Here again developmental test and evaluation is seen as essential for success.  A test to pass approach that does not return useful data is not desirable.  A detailed analysis of this approach can be found in SAE J1211: 2012.

Understanding Environmental Stresses

For any application of ruggedness design an understanding of the environmental stresses involved is essential.  This therefore requires an assessment and identification of all probable environmental factors, their frequency of occurrence, and intensities.  In MIL-STD-810 parlance this is accomplished through the development of a Life Cycle Environmental Profile (LCEP).  For automotive applications this is done through a Mission Profile.  These profiles should include all phases of product life including transit and storage.  They should also include lessons learned from similar product histories.  Once these stressors have been identified, their criteria can be used for development of design specification.  These criteria are also used to develop a test master plan with relevant stress values to be used in testing. 

CVG Strategy

Military and automotive applications require design and test methods that ensure ruggedness.  The development of a test and evaluation program that will verify a design and return significant data must be initiated at the concept stage of product development.  This is true when ruggedness is required of any product. 

CVG Strategy has experience in developmental test and evaluation for a wide variety of industries including military and automotive.  Because of this we understand looking beyond a test to pass perspective.  We can help develop a test program that will return meaningful data and verify a products ability to survive harsh environments.

Accelerometers and Laboratory Testing

Accelerometers and Laboratory Testing
Accelerometers and Laboratory Testing

What Test Witnesses Need to Know About Accelerometers and Laboratory Testing

Shock and Vibration analysis utilizing accelerometers and laboratory testing is a requirement for many commercial and defense standards.  Because accelerometers provide the feedback to the excitation system, proper selection and placement is essential.  To achieve optimal testing validity the test witness and test manager should have some knowledge about accelerometers and how they are used so as to provide valuable information to the laboratory personnel setting up the test.

Pre-test Preparation for Dynamic Testing

Having a fixture that is designed for your test item is optimal.  Having the same fixture to mount your test item on ensures that a test is repeatable.  This fixture should be characterized prior to testing so that no resonances or nulls to the shock or vibration profile are being introduced to the Unit Under Test (UUT).  Fasteners used should be characteristic of those to be used in the product’s intended installation and should be tightened to the specified torque.  Furthermore the UUT should be mounted on the fixture identically for all tests.

Know the Parameters of the Tests

Because of the wide range of possibilities, it is important that the test witness be aware of the characteristics of the profiles to be used in a dynamic tests.  These characteristics include the frequency range and the amplitudes.  It is a good idea to review this information from the test plan with the laboratory test engineer to ensure proper accelerometer selection.  Selection of an appropriate accelerometer is essential because of the wide variety of usable frequency range and amplitude scale.

Mounting of the Accelerometers

The method of mounting an accelerometer can greatly effect its frequency response.  Methods for mounting include stud mounting, adhesive, and adhesive mounting pad. 

When practical stud mounting provides the maximal frequency response.  Often a coupling fluid such as grease or beeswax is used to enhance frequency response to compensate for surface flatness or roughness.  If these are used the specific medium used should be documented so that the test parameters can be replicated. 

There are small differences between adhesives in their frequency responses.  Often Loctite 454 is used.  Generally these work well.  For testing where large forces are at play however, such as hammer shock tests used in shipboard shock and ballistic shock, adhesives are not advised.  These adhesives can fail during the test resulting in necessary retest and possible over test of the UUT.

Once the location of the accelerometer(s) have been established and validated the locations and means of mounting should be documented.  Documentation, preferably by photo, should also show the means of securing the accelerometer wiring because base strains caused by wiring can effect the response of the sensor.

Other Considerations

The vast majority of test laboratory engineers are well informed about the dynamic testing they perform on a regular basis.  They however, need to know about any specific information particular to the UUT.  If dynamic testing is to be conducted with the UUT in an operational state, areas that reach high temperatures should be noted.  If these areas are used for mounting the test engineer may have to utilize thermal compensation.  Additionally if the UUT generates extreme magnetic fields shielding might be required.

CVG Stategy Test and Evaluation Experts

CVG Strategy has performed test and evaluation for a wide range of commercial and military applications.  We have extensive experience in dynamic, climatic, and EMI/EMC.  We can provide test program management, test witnessing, test program documentation, and product evaluation.  Contact us to see how we can help you get the most from your test and evaluation program.

Effective Test Program Management for Better Products

effective product test management
effective product test management

Effective Test Program Management Requires Planning

Effective Test Program Management can add value to product development when its true value has been identified.  Too often product testing is left to the last moment, calls are made to test laboratories to ask what testing is required.  Equipment and somebody from the engineering team is transported off to a test lab and money and time is spent.  Hopefully testing is “passed” and requirements have been met to sell the product, but what has really been accomplished?

The Role of the Test Lab

Test Laboratories offer valuable services.  As such, finding a lab that can fill your requirements, provide flexible scheduling, and help keep the project in budget is important.  Maintaining good working relationships with those facilities is important.

The role of the lab, however, is by definition limited.  As an accredited third party evaluator they cannot act as an advocate for your product.  They can recommend a test matrix or provide a minimum criteria for product certification but ultimate responsibility for what testing is done lays with the test program manager.  Recommendations for testing should be reviewed in detail however as in many instances unnecessary testing may be performed. 

The Role of the Test Program Manager

Assessing Test Requirements

Developing a thorough understanding of relevant standards and compliance requirements is the responsibility of the test program manager.  Understanding the procedures to be performed will allow for proper scheduling.  It will also help in the development of appropriate fixtures, simulation equipment, and monitoring equipment.

Looking Beyond Compliance

Because product liability is becoming an increasing issue, product testing must consider testing beyond compliance requirements.  Performing a Life Cycle Environmental Profile and/or Susceptibility Analysis can be valuable in identifying product vulnerabilities.  A test matrix can then be created that includes appropriate evaluation methodologies to verify a design’s safety and ability to maintain customer satisfaction.

Test Program Documentation

Test Labs are beset with requests to perform testing without sufficient documentation.  While many types of testing are not tailorable, most standards still require documentation that provides descriptions of operational modes, power requirements, emergency shutdown procedures, and definitions of normal operation.  This documentation allows test lab personnel to make evaluations based on pass/fail criteria specific to the equipment being tested.  For those test methodologies that do require tailoring such as MIL-STD-810 or EN 61326-1:2013 test plans must be developed that specify procedures, severities, and appropriate data collection.

Hardware for Testing

Time must be taken to design and construct the equipment needed for test.  This equipment may include:

  • Vibration Fixtures
  • Extension Cables
  • Simulation Equipment
  • Stimulation Equipment
  • Monitoring Equipment
  • Dummy Loads

Care should be taken to consider test lab chamber and facility limitations when designing this equipment.  Simulation, stimulation, and monitoring equipment are extremely important in capturing intermittent failures.  This equipment is also required for pretest, during test, and post test functional and operational checks. 

Many people will have the test lab provide a vibration fixture.  Test lab fixtures are often in a constant state of modification as customers drill holes for their tests.  This means that even if the same piece of hardware is available at subsequent tests it will not be the same as when used before.  This may degrade the ability to accurately recreate previous testing.  Therefore it is considered a best practice to have a custom fixture.

Test Witnessing

Effective test program management requires active test witnessing.  Care must be taken to ensure that testing is performed as prescribed in the test plan.  Proper set up and pre-test operational testing should confirm that the equipment under test is working and functional.  Test witnesses can often assist lab personnel by monitoring equipment and confirming the status of the equipment.  Test witnesses should also collect data over and beyond that required by the lab so that test can accurately be reproduced.  Should any failure of test be encountered, the test witness should gather all data relevant for later analysis.  The witness should also, when appropriate, troubleshoot and determine root causes for failures.

Documentation

Documentation of testing should be created from test witness gathered data and test lab reports into a summary document that provides an overview that can be used to show due diligence and act as a guide for future product development in term of “lessons learned.  Any certifications or right to mark with regard to compliance testing should be noted as well.

CVG Strategy

CVG Strategy’s Test and Evaluation experts offer Test Program Management and Witnessing to assist you in getting real value from your testing program.  Contact Us to see how we can put decades of experience in commercial and defense testing to work for you.  Our experience includes climatic, dynamic, and EMI/EMC.

MIL STD 810H Humidity Method 507.6, A Deeper Look

MIL STD 810H Humidity
MIL STD 810H Humidity

MIL STD 810H Humidity

MIL STD 810H Humidity Method 507.6 is a test method for evaluating products that are likely to be stored and/or operated in a warm, humid environment.  MIL-STD-810 Environmental Engineering Considerations and Laboratory Tests is a Department of Defense (DoD) standard for military and commercial applications.  It is a series of laboratory test method that replicate the effects of environments on products.  These methods are meant to be tailored to the specific environmental effects expected during the life cycle of the product.  This is an important consideration because there are few definable goal posts in this standard.  Tailoring is required because the environmental effects likely to be encountered on equipment designed for aircraft, for example, will be quite different from those found on a vehicle.

Effects of Humidity

The effects of humidity are often overlooked when faced with more obvious environmental stressors such as temperature, shock, and vibration, but there are numerous physical and chemical effects that humidity can take place both within and on the exterior of equipment.  For surface effects; oxidation, electrochemical breakdown of coatings, interaction with deposits of materials that produce corrosive films, and changes in friction coefficients.  Other effects include; loss of physical strength of materials, degradation of insulative properties, changes in elasticity or plasticity, and degradation of lubricants.

Humidity Testing

Humidity is an extremely complex environmental phenomena that is intricately linked with temperature.  There a limitations in what a laboratory method can reproduce and simulate.  Method 507.6 is comprised of two procedures.

  1. Induced (Storage and Transit) and Natural Cycles
  2. Aggravated

For procedure I, induced cycles of temperature and humidity are used to simulate various storage and transit scenarios where equipment is packaged or stored in environmentally uncontrolled warehouses.  The standard points out that multiple tests may be applicable for storage or transit based on the nature of those sequences and nature of packaging.  Natural cycles are intended for the testing of equipment in its intended environmental conditions.

Procedure II exposes the test item to more extreme temperature and humidity levels than those found in nature, but for shorter durations.  While this can be an advantage for early detection of design vulnerabilities, results may not accurately represent those found in nature.

Climatic Considerations

Conditions of humidity vary considerably across the globe.  MIL-HDBK-310 defines three geographical categories that are used for generation of cyclic profiles.

B1 – Constant High Humidity

This profile is representative of conditions found in heavily forested areas with little solar radiation exposure.  Geographical locations typical of this profile are Congo and Amazon Basins, the jungles of Central America, Southeast Asia (including the East Indies), the north and east coasts of Australia, the east coast of Madagascar, and the Caribbean Islands.

B2 – Cyclic High Humidity

B2 profile occurs in the same areas as B1 but is more representative of urban areas where solar radiation exposure is expected.  Solar radiation when present in the diurnal cycle creates a wider variance in temperature and humidity.

B3 – Hot-Humid

This profile is found in areas near bodies of water with high surface temperatures, specifically the Persian Gulf and Red Sea.  Testing for this extreme condition does not verify the unit under test’s ability to endure the rigors of B1 or B2.

Additional Categories

Additional categories are provided for induced environments where temperatures as high as 160 °F (66 °C) can be reached for enclosed environmental conditions where little or no cooling air is available.  These induced categories are meant to replicate various transport and storage scenarios.

Test Duration

The effects of humidity require lengthy test durations to evaluate potential degradation.  Often testing is not performed at adequate lengths to provide meaningful data.  MIL STD 810H Humidity Method 507.6 durations are shown in the table below.

Hazardous Items

MIL-STD-810 states that hazardous test items will generally require longer tests than other items to achieve a desired confidence.  The standard defines Hazardous test items as “those in which any unknown physical deterioration sustained during testing could ultimately result in damage to materiel or injury or death to personnel when the test item is used”.  It calls for double the number of cycles for hazardous items. 

Non-Hazardous Items

For Natural Cycles, generally intended for operational testing, Method 507.6 calls for 15 to 45 tewnty-four hour cycles of testing dependent on which geographical area the equipment may be used in.

Aggravated Cycles

For Aggravated testing per Procedure II, ten cycles are recommended in addition to a 24 hour conditioning period.  Again the proviso for lengthening for hazardous items is called out but no exact measure is indicated. 

MIL-STD-810 H Table 507.6 II Test Cycles (days)

The Conundrum

For humidity testing there is often more questions than answers.  Today’s defense and commercial equipment is liable to be used anywhere in the world.  Given that time and money are major concerns for most product developers, it is unlikely that resources are available for testing all climatic categories for transit, storage, and operational profiles.  While Aggravated testing is tempting due to its shortened test length it may not provide realistic findings.  Unless product specifications specify exact testing requirements difficult decisions must be made. 

CVG Strategy

CVG Strategy’s test and evaluation experts have decades of experience in environmental (climatic and dynamic) testing as well as EMI/EMC.  We offer a wide variety of services including: EZ-Test Plan Templates, Test Program Management, Test Program Witnessing, and Product Evaluation.  We also provide a two day seminar/webinar “Understanding MIL-STD-810” to help your product development team garner the most from their test and evaluation programs. Contact Us today to see how we can help.