NTS News Center

Latest News in Testing, Inspection and Certification

NTS News Center - Latest News in Testing, Inspection and Certification

FAA Fire Testing at NTS

FAA Fire TestFire and flammability testing is required for products used in a wide range of industries, NTS fire and flammability testing services typically fall into two categories: 1) ignition and flame spread, and 2) fire resistance. The Federal Aviation Administration calls out a number of standards NTS conducts testing to for our aviation customers.

FAA Fire Testing Specifications

  • RTCA DO-160 Section 26
  • ISO 2685
  • FAA AC20-135
  • FAA Powerplant Engineering Report No. 3A
  • FAR Part 25

Meeting these test specifications requires specialized burner equipment as well as customized fire rooms for the safety of the technicians, engineers and customers witnessing their test. The specifications call out various burn lengths, the distance from the original edge to the farthest evidence of damage to the test specimen due to flame impingement, and burn time to failure of components depending upon the component being tested, for example 60 seconds is the specification for interior compartments housing crew or passengers.

NTS utilizes liquid fuel burners, both vertical Bunsen type and horizontal (pictured above). The flame temperature for the burners reaches the required 150°F ± 2000°F (1100°C ± 80°C). The heat flux of these burners are at least 4500 Btu per hour (116 ± 10kW/m²).

Contact us today to learn more and discuss how NTS can help you with all of your safety-of-flight qualification testing! Click here to get started.

Reverberation Chamber Workshop Coming to Fullerton!

reverb-600x240We are pleased to announce that we will be hosting the IEEE Los Angeles EMC Chapter and MTT/AP Joint Chapter Meeting at NTS Fullerton, CA location on October 17.

This workshop will address fundamental to advanced topics regarding reverberation chamber test methodology, including the new applications for this versatile and robust test environment. Once mainly used for Government test requirements, the reverberation chamber is increasingly being used for aerospace, automotive and consumer electronic test applications due to its inherent efficiencies in cost and time. Practical, application oriented material will be provided that you can use on the job. The workshop concludes with a live demonstration of a EUT using the reverb chamber at NTS.

Speakers include Garth D’Abreau, Director of Automotive Solutions at ETS-Lindgren, Dr. Vignesh Rajamani, Senior Associate at Exponent, and Jeff Viel, Corporate Director of EMC at NTS.

Click here for more information and to register. If you would like more information about the NTS Fullerton reverberation capabilities, click here.

NTS offers CAD/FEA Modeling for Direct and Indirect Effects Lightning, Reducing Test Costs and Time

The NTS Lightning Technologies laboratory in Pittsfield, MA is now offering finite element analysis, allowing the performance of complex simulations that accurately model the interaction of lightning with a variety of aircraft and avionics components for our customers. This service is available to all of the customers of the 10 NTS facilities across the US offering direct and indirect lightning testing.

Lightning Testing Figure 2

Figure 1 – Current Distribution and Magnetic Field in Two Current Carrying Copper Conductors

By decomposing complex CAD-generated objects into meshable geometrical shapes, these models are able to accurately portray the lightning environment (current distribution, electric and magnetic fields, pressure waves, temperature variations, induced transients) on high fidelity renditions of real objects. Once the geometry is built, highly customizable material parameters, boundary conditions, and applicable physics interfaces (Maxwell’s Equations) are applied that generate a system of equations that is solved in COMSOL. With accurate representation of test object geometries, the solutions of these models allow for conducted and induced transients to be determined at any point in the model.

Figure 2 - Magnetic Field Penetration through Apertures on a Fuselage

Figure 2 – Magnetic Field Penetration through Apertures on a Fuselage

Utilizing simulation and modeling along with laboratory testing provides customers with a new, cutting edge way to obtain valuable test data that can reduce testing costs substantially. Making use of these models allows for the easy acquisition of difficult or impossible to obtain lab measurements (equipment limitations) without having to perform the test on an actual object. Once a model has been developed, a similar test is performed on a real piece of equipment in order to validate the model. Once the model has been validated, lightning attachment locations, cable routing configurations, and material characteristics (to name a few) are all easily modifiable to allow for many permutations of the test environment to be modeled. The results of these models can provide valuable design constraints and necessary test levels for certification. Additionally, once validated, these models can serve as a firm basis for similarity analyses for future design changes, providing the potential for a cost and schedule reduction to future programs.

Figure 3 - Magnetically Induced Voltage on Conductor inside Fuselage

Figure 3 – Magnetically Induced Voltage on Conductor inside Fuselage

For questions about our new finite element modeling and how it can be applied to your testing program or for any other lightning test related inquiries please contact our General Manager Mike Dargi at 413.499.2135 or Mike.Dargi@nts.com

NTS has 10 facilities across the US capable of performing your complex direct effects and indirect effects lightning testing. We are able to meet the full scope of RTCA DO-160 testing, as well as numerous other specifications with lightning requirements including MIL-STD-461/462, SAE ARP 5416A, and IEC 61400-24 (wind turbines). Contact us today to discuss your next test program.

Solar Radiation Testing in Accordance with Method 505 of MIL-STD-810

MIL-STD-810 Procedure 2 Solar TestingSolar radiation (sunshine) testing is one of the basic tests required for any military equipment planned to be deployed in the open and therefore subject to direct radiation from the solar source. The effects of this radiant energy can generally be divided into two groups or classes, heat effects and photochemical effects. Heat effects on exposed equipment can raise the internal temperatures of the equipment substantially above the ambient air temperature. Temperatures in excess of 160oF have been recorded in parked aircraft exposed to the sun while ambient air temperature was in the 90oF range. Photochemical effects of sunlight may hasten the fading of colors and lead to the deterioration of plastics, paints, rubber and fabrics. The combined effects may lead to the outgassing of plasticizers in some materials along with discoloration and a reduction in transparency.

MIL-STD-810, Method 505.5 outlines two procedures for performing the Solar Radiation test. Procedure I requires a cyclic exposure based on the diurnal cycle and is most useful for determining heating effects on exposed materiel as well as materiel enclosed within a container. Procedure II is a steady state (non-cyclic) exposure most useful for evaluating actinic (photochemical) effects of ultraviolet radiation on materiel since it represents an accelerated test with a factor of 2.5. Because Procedure I is more akin to a natural cycle and does not have the acceleration factor of Procedure II, it is not an efficient cycle with which to evaluate long term exposures. Therefore, when it is used mainly to evaluate the direct heating effect, Procedure I can be performed with source lamp arrays emitting less than the full solar spectrum. Procedure II however, demands full spectrum sources emitting light in the ultraviolet range if the total effects of long term exposure are to be properly evaluated.

The solar light spectrum has been accurately measured over the wavelength range of 280 – 3000 nm as well as the power distribution within this range, and it is this range that we would seek to reproduce in the Solar Radiation test.  Reproducing this entire range using lamp sources however can be quite challenging. Sources emitting ultraviolet wavelengths between 280 and 400 nm tend to be quite costly and their performance deteriorates quickly. Some of the MIL-STD recommended sources such as xenon arc and carbon arc fall into this category.  In fact, it was reported that the first commissioned sunshine test facility in 1945 fell short of the contract requirements due to several deficiencies, one of which was the amount of UV that could be produced at the test item. Cost and reliability issues are why many test labs have chosen to perform only Procedure I  with source lamps covering the visible and infrared spectrum range of 400 – 3000 nm (0.4 – 3.0 µm).

Reproduction of the required environment for the Solar Radiation test requires a chamber space in which the ambient air temperature and airflow over the test item can be controlled as well as a solar light source which may consist of a single source in the case of arc-type lamps or a multiple source array in the case of metal halide or incandescent type lamps. The distance of the light source from the test item may be varied to achieve the required irradiance. Airflow over the test item can significantly impact test results. When MIL-STD-810D introduced the “cycling for heat effects” (Procedure I) the guidance for airflow was to use airflow as low as possible consistent with achieving satisfactory control of the ambient air temperature at the test item or between 0.25 and 1.5 m/s (50 to 300 ft/min). The current guidance from MIL-STD-810G has changed for procedure I to 1.5 to 3.0 m/s (300 to 600 ft/min) in recognition of better field data. The requirement for peak radiation intensity at 1120 W/m2 has changed little over the history of the Solar Radiation test although there have been slight changes to the spectral energy distribution based on updated measurement techniques of the actual solar source.

When the primary concern is testing for heat effects, the question is often asked why an oven or chamber test for enclosed equipment could not be used in place of the Solar Radiation test.  The primary reason is that ovens and chambers transfer heat from a uniform ambient atmosphere surrounding the test item, whereas the solar test transfers heat through direct radiation. The directional effect of radiant heating produces temperature gradients through the test item that are not replicated in ovens or temperature chambers.

When a Solar Radiation test is required,

  • Perform the Solar Radiation test prior to the High Temperature test, as the product temperature measured in the solar chamber may need to be used as the ultimate high operating temperature for the product.
  • Consider the orientation of the test item within the solar chamber so as to replicate the in-use conditions with respect to both the direct radiant light energy and the airflow direction. This will affect both the temperature gradients and any cooling effects provided by the airflow.
  • When testing to Procedure I, remember that several consecutive cycles will likely be required for the product to achieve the ultimate high operating temperature for the most critical area of the test item to be within 2oC of the previous cycle. This usually means 3 to 7 cycles.
  • If operation of the test item is required, operational times will need to coincide with the peak response temperature of the test item in each cycle which will not coincide with the peak radiation intensity.

How can I relate the results of MIL-STD-810 salt fog testing to the life time of my product?

This is a very common question that we get asked quite often and unfortunately there is no correlation between what the product sees in the salt fog chamber to what it will experience out in the field. In order to understandSalt Fog Testing why, you must first understand the purpose of the test.

Originally stated by V.J. Junker in The Evolution of USAF Environmental Testing(1), the test is to determine the resistance of aerospace ground and aerospace equipment to the effects of a salt atmosphere.

According to Mil-STD-810G, the test is performed to determine the effectiveness of protective coatings and finishes on materials. The stated purpose of the test is to determine design flaws such as dissimilar metals, improper coatings, uncoated materials, electrolytic action, binding of parts, etc. Therefore, results can be related to the suitability or quality of parts or assemblies, but cannot be directly related to exposure time in the marine environment.

Salt Fog and Salt Spray testing are conducted at 14 NTS locations across the country. Visit our locations page to find the lab closest to you!

(1) Junkers, V.J. The Evolution of USAF Environmental Testing, Technical Report AFFDL-TR-65-197, October 1965.

Is there a preferred sequence for EMI, EMC Tests?

EMI Testing NTS BoxboroughOne of the questions we get asked often is about order of EMI/EMC testing.  Neither MIL-STD-461 nor RTCA/DO-160 specify the order of test performance.  Leaving aside the issue of Safety of Flight tests for aircraft (which typically must be performed prior to any other testing), there are a few different approaches to take in this regard.

The first approach is to perform an analysis of the equipment under test (EUT) before going to the lab to determine what tests are most likely to cause problems, and to start with them.

This approach works best if a customer does not have any idea how their product will stand up to the EMI/EMC compliance requirements. A design analysis tends to vet out significant concerns up front, potential design solutions can be discussed prior to qualification testing. At this point, the Subject Matter Expert (SME) should be able to prioritize the threats, and work with the customer to develop a suitable test order. This approach also provides an opportunity for pre-qualification evaluations to ensure the product will not have any issues during the qualification program.

The second approach is to begin with the most benign tests, usually the emissions.  These tests have virtually no chance of harming the EUT, but they sometimes prove to be the most problematic.  Emissions testing tends to reveal inerrant design flaws the most, and generally requires some level of redesign. Changes in design could necessitate repeating other tests if emissions is not completed first. However, there may be cases were a customer feels their product does not have any emissions concerns but is likely to be susceptible to a particular immunity test. They may choose to get the immunity evaluation out of the way first, and allow time for potential modifications prior to commencing with the remaining tests. This approach would also avoid costly retests or delays due to changes to the EUT.

The third approach is to begin with the most potentially damaging tests first. The philosophy here is that all is well and good if the EUT endures those tests with no issues.  However, if there are susceptibilities that require repair/redesign, those problems can be resolved before continuing with the other tests.

In summary, the EMC / EMI testing sequence used should be an iterative decision between the lab and the customer to determine which approach best suits the product and customer’s needs.

NTS Quick Guide to Reverberation Testing


Inside the RF chamber

A reverberation chamber (mode tuned/mode stirred chamber) is a shielded enclosure or resonant cavity for RF testing which is statistically isotropic, random polarity, having RF uniformity within specified limits. Typically it has a paddle (or tuner) which stirs up the field, randomizing the boundary conditions. Mode tuned is where the paddle is stepped to a position and then RF is applied for a dwell time sufficient to exercise the equipment. Mode stirred is when the paddle is continually turned with RF energy applied for a full paddle revolution. Reverb chambers are useful for radiated susceptibility, radiated emissions (total radiated power), shielding effectiveness, and many other troubleshooting scenarios.

The benefits to reverberation testing are numerous. RF is applied to all exposed sides of the device under test (DUT) during a full 360° turn of the paddle, instead of a single side. For direct illumination testing, many standards require the all apertures of the DUT to be illuminated. On complex items this can be difficult – even impossible. Window effects testing, required when applying direct illumination, is not required during reverb testing because the field intensities are constantly changing. SAE ARP 5583 states that the reverb is the recommended and preferred method to show compliance for large and/or complex Level A (flight critical) systems. Test repeatability is much easier to obtain in a reverb chamber with proper processes, and running the test is much less complex than a single aspect angle test. Antenna distance, aim (focus), 3 dB beam width, location of the field probe, EUT layout, and location of the EUT in the working volume are all less of a factor in the repeatability of test.


A view from outside

You should know if reverberation testing is right for your program. Reverb chambers are random in polarity which makes it challenging in determining directivity of RF energy. Testing multiple field levels on a system, such as outside the pressure vessel level and inside the pressure vessel level, can be difficult; all equipment in the chamber is exposed to the same field. There are limitations on pulse width due to a high Q (efficient) chamber having large amount of stored energy. If you have small, simple equipment, single aspect angle tests may be faster and sufficient for test coverage. There are ways to compensate for each, and an NTS engineer can help with suggestions or assist you with a test plan.

Both direct illumination and reverberation test methods are acceptable paths to certification. They both have benefits and drawbacks that champion each as a test method. Fortunately, NTS has the ability to test in both methods and the engineering expertise to support your path to certification.

For more detailed information about reverberation testing at NTS Rockford, Fullerton, Plano, Tempe, or Boxborough, call 800-270-2516 or email us at sales@nts.com. Request a quote today!

MIL-STD-461G Released

MIL-STD-461 Testing at NTS

The G revision of the MIL-STD-461 standard was released in December 2015 and is available here. NTS’s Jeffrey Viel’s wrote an article for InCompliance Magazine reviewing the proposed changes which was published back in August 2015. These changes have carried into the final released standard and are worth reviewing.

A few highlights of the MIL-STD-461G standard:

  • FFT receivers are now permitted for use
  • Interconnecting cable routing now specified for floor standing equipment
  • Test method CS106 has been removed
  • Test method CS114 system check updates
  • The addition of test method CS117, conducted susceptibility, lightning induced transients, cables and power leads
  • The addition of test method CS118, personnel borne electrostatic discharge
  • Test methods RE102 and RS103 technical updates

Contact NTS today to discuss your next MIL-STD-461 test program.

The Benefits of Pre-Compliance EMC Testing

EMC Pre Compliance Testing

One of the biggest product development challenges today is ensuring electromagnetic interference is optimally controlled. With proper electromagnetic compatibility (EMC) testing and design, you can ensure the correct operation of various devices in the same electromagnetic environment. EMC is achieved by addressing both emission and susceptibility issues by taming the sources of interference and by strengthening the potential victims.

EMC Testing

A number of international EMC standards are in place to standardize product EMC performance. The FCC and CE are two of the most common EMC standards. Electromagnetic compatibility testing is broadly divided into
emissions testing and immunity testing.

EMC Emissions Testing

EMC emissions involve two types of testing: radiated emissions and conducted emissions testing. With radiated emissions tests, the goal is to check for unplanned emissions that exceed a given pass band as defined by the class of the product. Conducted emissions testing involve shorter frequency range — for example, 30 Hz to 10 KHz.

EMC Immunity Testing

Immunity testing is required for EMI compliance in the U.S. for medical devices and for a wide range of consumer products in the EU. A number of immunity tests may be required depending on the type of device and its application.

Pre-Compliance EMC testing

EMC testing is time-consuming, and failed tests can delay product launches. Your budgets will be stretched, and your reputation is at stake if you are not meeting customer’s demands. Many devices fail during EMC testing, often during radiated emissions testing.

By building EMC testing into the product design and development phases from day one, one can build a product that has a lower risk of failing EMC tests at the end. With pre-compliance EMC testing, you perform EMC tests and incorporate best practices throughout the design and development process. This allows you to meet EMC compliance more easily and effectively during your final testing.

Pre-Compliance EMC Testing Is Important

The best way to avoid expensive retesting and noncompliant EMI issues is by checking for emissions from your device throughout the product development cycle. Pre-compliance EMC testing has multiple benefits.

  • Detect Errors Upstream in the Product Development Cycle


The earlier in the product development cycle you can identify issues with emissions, the easier it is to correct the issues. Also, the solutions or options to correct EMI are more in the early stages of product development versus later. Correcting EMI issues after compliance testing is costly and results in loss of precious time versus fixing upstream in the design phase.

Imagine leaving EMC testing of your device at the end of the development of the product. Any issue that may have been smaller and possibly easier to isolate early on is now more complex and amplified due to more parts and subsystems within your device. For example, it’s much cheaper to make an EMC fix on a circuit board versus correcting once the design is final. As a specific example, a resistor-capacitor low-pass filter on data signals before crossing a radiating cable may cost you .1 to .5 cents per PCB. However, if the PCB is finalized and you need to solve against the radiating cables, a cable choke will cost you more than $1 per cable.

Mechanical changes, EMI shields, use of EMC foam and other design changes are made to counter emission issues. When EMC testing is done early, it allows you to make better decisions on types of changes to make to become EMC compliant.

  • Integrate Pre-Compliance Testing Into Product Development

When testing is integrated into product development, one can tap into a well-known testing company for ongoing support. It can provide testing infrastructure and subject matter experts during the entire product development cycle. This is an upfront investment that pays off by keeping your project on time and by reducing risks from noncompliance.

Experienced design engineers that offer pre-compliance EMC testing as part of their suit of services will continuously look for areas of risk during product development. For example, testing during product development can provide the designer options to add in preventative measures in the form of additional circuitry, or other mechanical or system design changes. When product designers come up with a fix, it is helpful to test it immediately before making major design changes.

  • Eliminate Overdesign

If you are not performing pre-compliance EMC testing, you may be overengineering your product to ensure it meets EMC compliance at the end. Since you are not testing along with design and development, you may be adding countermeasures which may be redundant. These measures may considerably add to your product cost.

Overdesign or overengineering is common across various industries. This can include coding for software, designing automobiles or airplanes, or design of bridges and building structures. With pre-compliance testing, you have the option to test more often and throughout the design and development. This can help you to avoid using parts with higher-than-necessary specs or even avoid parts you may be incorporating to stay EMC-compliant.

  • Design for EMC Compliance

This is not a test, but it’s one of the most ignored pre-compliance strategies. You can do a detailed and systematic schematic and layout design review as part of your pre-compliance processes. This can significantly reduce the risk of your product failing at an EMC test lab.

You can detect many potential emissions and immunity issues in a design review. A solid design review will catch many of the root causes of emissions and immunity problems even before your first test PCB is created. If you do not have in-house expertise for EMC-compliance design, work with a testing company that can provide this service. This can increase your first-time pass rate.

Pre-Compliance EMC Testing Options

Pre-compliance EMC testing can be done by hiring a testing lab or by doing it on your own once you have the right equipment and testing gear.

  • EMC Testing Lab

You can rent equipment and hire personnel from a testing company for pre-compliance testing. Professional testing labs have fully compliant test gear, which will allow you to perform tests with high accuracy. A reliable test lab will also be able to assess your test device and provide recommendations on potential root causes. This way, you can focus on addressing those as part of your pre-compliance effort. Some labs can provide turnkey pre-compliance and final compliance services as one package, which can keep your overall costs low.

Advantages to this approach include:

  • Your test results have a high level of accuracy since the same testing equipment is also used for final compliance testing
  • You don’t need to invest capital to procure test equipment
  • You get absolute measurements when performing emissions testing. If you do this on your own, you get measures which are relative

About NTS’s EMC Testing

NTS offers a wide range of services to help clients meet EMC compliance across various industries – consumer, industrial, automotive, medical, military, space, aircraft, telecommunications, etc. Our range of EMC/EMI services includes engineering, design analysis, testing and technical training.

NTS also has the largest network of commercial EMC testing labs in North America. We have a deep knowledge of various EMC compliance standards, and we are fully versed in FCC and CE standards and testing requirements.

Our labs and equipment use the latest technology and are powered by the most respected and experienced engineers and technicians. We have people, processes, tools and knowledge capabilities that allow us to test to extreme limits and complex standards.

We offer a wide array of EMC and EMI testing services:

Electrostatic discharge (ESD)

Electrostatic discharge (ESD) testing measures a device’s ability to tolerate discharge events. These events occur when a user touches the device and another metallic surface at the same time.

Harmonics and flicker

Harmonic frequencies greater than 50 Hz and voltage dips in the 5 to 15 Hz range can cause harmful interference for electronic devices. Devices need to be tested under these conditions to meet EMC compliance.

Electrical fast transients

Electrical fast transients testing (EFT) simulates a common type of real-world interference which was previously neglected. EFTs involve a high-frequency disturbance on a power line which occurs as a result of inductive loads being turned on or off.

Voltage dips and interrupts

Testing for voltage dips and interrupts (VDIs) involve simulating the conditions of voltage dips and voltage interruptions. The device is tested in the simulated environment to assess tolerance against VDIs.

Electrical surge

Surge testing is a key part of EMI analysis. NTS produces a low frequency, high energy electrical transient to simulate the effects of a lightning strike on a nearby power line. The device’s response is measured under these stringent conditions to test its tolerance against the surge.

Radiated susceptibility up to 200V/m, 10kHz to 40GHz

Military and Aerospace applications commonly require radiated susceptibility tests. NTS can perform radiated immunity testing up to 200V/m field strength in accordance with various military standards from 10kHz to 40GHz.

HIRF testing

High intensity radiated fields (HIRF) are divided into three frequency bands. HIRF-testing-frequenciesEach of these bands can affect airplane electronics in various ways:

  • Low frequency electromagnetic emissions between 10 kHz
    and 50 MHz
    — Low frequency HIRF use electrical parts like an antenna, carrying currents in the fuselage skin. These create little interior penetration.
  • High frequency electromagnetic emissions in the range of 100 MHz and 18/40 GHz — High frequency HIRF generates strong field penetration into the fuselage.
  • Medium frequency electromagnetic emissions between 30 MHz and 400 MHz — Medium frequency HIRF combine both LF and HF emissions effects. As a result, these emissions mimic both of the antenna-like performance as well as fuselage penetration.

HIRF certification generally involves measuring transfer functions to estimate the potential effects of EMI on an aircraft. NTS employs a variety of tools and techniques to produce accurate testing that is fully compliant with all required specifications.

NTS can help you meet requirements for HIRF certifications including RTCA/DO-160E/F, Boeing and Airbus requirements, and FAA HIRF Rule & Advisory Circular 20-158.

Lightning-multiple stroke, multiple burst and single stroke

NTS has lightning simulation capabilities that include:

  • Single Stroke
  • Multiple Stroke
  • Multiple Burst
  • DO-160 Section 15-22
  • Radiated Fields 200 +V/m
  • Electrostatic Discharge

We can precisely measure direct and indirect effects of a lightning strike. When it comes to direct effects, a lightning strike causes damage due to temperatures exceeding 20,000°C and electric spikes of more than 250,000 amperes. To simulate these conditions, NTS facilities have a series of high current generators and an indoor test area that measures 40 x 120 feet.

A lightning strike can also create a temporary rise in earth voltages after an impact. This indirect effect creates an intense electromagnetic field that can harm equipment up to a radius of one kilometer. NTS can run a variety of tests, including pin injections, transformer injections, and field immersions to determine the indirect effects of lightning. Together, these tests allow our engineering team to perform a thorough field and transient analysis. This further allows us to assess the indirect effects of a strike on everything from individual circuit parts to complex interconnected electronic systems.

MIL-STD-461 Testing

The MIL-STD-461 is a standard of the Department of Defense (DoD) that describes how to test equipment for electromagnetic compatibility. Even if this standard isn’t required, a device complying with this relatively strict standard will comply with most other common standards.

NTS can also help you with additional tests:

  • Magnetic susceptibility dc to 10kHz
  • Full CE immunity
  • Mode tuned chamber

EMC/EMI Engineering Services

Besides specific testing, NTS has the know-how to consult you on various engineering services related to EMC/EMI:

  • Electromagnetic environmental effects (E3) analyses of systems and platforms
  • EMC control plan
  • Independent EMI/EMC reviews
  • NARTE-certified engineers
  • Performance requirements definition and flow down
  • Requirements gap analysis
  • Risk mitigation plans
  • System EMC design
  • Test procedures and corrective action

Contact NTS for EMC Solutions

NTS testing labs can provide comprehensive HIRF and other electromagnetic interference testing for today’s most demanding clients and standards. NTS is the nation’s largest independent product testing and standards compliance organization. We regularly service the needs of military contractors, avionics manufacturers and more.


NTS is renowned globally as an industry leader in providing EMC and EMI engineering and compliance services. Our experienced program managers and veteran engineers work closely with you to meet your EMC pre-compliance needs from conception, design and development to final test and production. We have expertise in various EMC/EMI engineering services to perform a variety of tests to meet standards across multiple industries and geographies.

With more than 50 years of experience, NTS has a long list of satisfied clients in our portfolio. Clients include organizations like Boeing, Cisco, U.S. Department of Defense, EMC, General Electric, Hewlett-Packard, Lockheed Martin, Microsoft, Motorola, Sony, Pratt & Whitney Rocketdyne, Texas Instruments and Tyco Electronics Corp. Contact us today to learn how we can help your business.

Why do I need EMC Compliance?

EMC TestingThere are a variety of reasons why your electrical/electronic products may be required to go through the Electromagnetic Compatibility (EMC) compliance process.

Regulatory Requirements

Most industrialized nations have established agencies or other regulatory bodies responsible for defining and enforcing EMC standards. If EMC regulations exist in a country, equipment manufacturers cannot legally ship their product into that country until compliance with those regulations is met. Professional compliance laboratories like NTS understand the global compliance process and possess the accreditations and capabilities needed to perform testing and certification to meet the relevant standards in all of your target markets.

Customer Requirements

There are many situations in which your customer may dictate EMC requirements. For example, if your customer is an RBOC (Regional Bell Operating Company), an extensive set of tests referred to collectively as Bellcore, are required before the RBOC will purchase your product. If your product or component will be included in a third-party product, your OEM customer will need proof that your product or component will meet appropriate regulatory standards. Your OEM customer will dictate the amount of testing and documentation they require. It is not unusual for an OEM customer to ask for compliance exceeding legal requirements.


In some cases, you may want to self-impose reliability standards for your products; for example, if you only plan to ship your product in the United States, unlike in Europe, you are not required to pass immunity standards. However, you may want to establish your own immunity standards to ensure customer satisfaction by minimizing field failures.

How do I achieve EMC compliance?

Determining Relevant Standards

The first step in the compliance process is to determine the list of target markets where you plan to market and sell your products. Compliance regulations vary from country to country, so an investigation of current standards is required for each market where you intend to operate. Countries such as India have no formal Electromagnetic (EMC) requirements, whereas Taiwan has a very strict submission policy.


Over the past several years, regulatory agencies around the world have been moving away from agency submittal applications because they are slow and inefficient. Most government agencies now allow for self-testing and self-certification. This means that you can simply affix a CE or FCC mark to your product and begin shipping without gaining government regulatory approval first.

However, self-testing and self-certification does not relieve your company from meeting the standards implied by the mark you place on your product. In fact, if you place a mark on your product when it doesn’t comply, it could result in serious consequences.

NTS has the formal accreditations to provide both the testing and the reports you need to meet a wide range of regulatory self-declaration requirements. We also create the reports that you must keep on file should an issue arise requiring proof of compliance.

Third party Verification

This is the process of having an independent party validate a product’s compliance. Third party verification adds significant credibility to a product’s test/compliance program, either for marketing or regulatory purposes.

Formal Certification

With certain types of products and in certain countries, a formal certification process may be required. For example, in Taiwan, a formal submission and approval is required, whereas the European Union might allow self-certification. In the USA a formal FCC submission, called a Certification, is required for any products designed to transmit radio signals. In addition to the testing costs to meet the relevant standards, you should also expect to pay agency submittal fees ranging from a few hundred to a few thousand dollars depending on the country and the type of product.