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Latest News in Testing, Inspection and Certification

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

EMC Field Probe and Time Domain Workshop – Co-hosted with ETS Lindgren

NTS Chicago is pleased to host a dual seminar and workshop with ETS-Lindgren on May 4, 2017 at our new facility in Mount Prospect, IL.

The presentations “Understanding EMC Field Probes” and “Time Domain Measurements for Test Site Validation and Diagnostics” will be given by Zhong Chen, Director of RF Engineering at ETS-Lindgren, a 20-year veteran of the industry with extensive experience in RF testing, anechoic chamber design, and EMC antenna and field probe design and measurement.

The meeting will be held May 4, 2017, from 4:30 pm to 8:00 pm with a bread for dinner and a facility tour at 5:30 pm. Register by April 27 to reserve your spot! Click here to visit the registration page.

Advanced Testing Technology Meets Art Conservation: NTS lab assists in the digital exploration of medieval boxwood sculptures.

Thanks to the help and participation of our NTS Chesapeake Non-destructive Imaging Laboratory (formerly Chesapeake Testing), researchers have made advances in the study of medieval boxwood sculptures. The pieces are currently being featured in the exhibition Small Wonders: Gothic Boxwood Miniatures at the Met Cloisters, the branch of the Metropolitan Museum of Art dedicated to medieval art and architecture.

These intricately carved objects, some over 500 years old, are simply miraculous in the level of detail created in such small objects. The 3D digital data captured via micro CT scanning helped researchers shed light on the techniques and craftsmanship required to construct these pieces of art with such fine detail.

Micro CT scanning, much like medical CAT scan imaging, uses the material penetrating properties of x-rays to provide information from within an object, whiteout any destructive effects. Unlike medical CAT scanning, micro CT has the ability to obtain extremely high resolution images, thanks to the use of highly focused x-ray sources and higher resolution imaging panels.

This data gives historians and researchers a unique ability to virtually cross section the artifacts, without any risk of damage. In addition to being able to analyze the internal structure, the scanning process also captures full 3D surface information which can be used later on to 3D print replicas and allow for enriched public interaction with these delicate pieces of medieval history.

To learn more about these fantastic carvings, visit The Met website here: http://www.metmuseum.org/press/exhibitions/2016/small-wonders. The exhibition runs from February 22 through May 21, 2017.



Upcoming Changes for Wireless Equipment in the 5 GHz Band EN 301 893

By Deniz Demirci, Senior Wireless/EMC Engineer, NTS Silicon Valley 

Manufacturers of wireless devices operating in the 5 GHz bands intended sale in the EU should take note of some important changes.

Draft version of EN 301 893 V2.0.7 has been published in the ETSI web site in order to align with the Article 3.2 – Essential Requirements of Radio Equipment Directive 2014/53/EU.

Currently, manufacturers of these type of equipment can still use R&TTE Directive 1999/5/EC (Radio and Telecommunication Directive) and it’s harmonized standard EN 301 893 V1.8.1 in their Declaration of Conformities (DoC) until June 13, 2017.

After this date, manufacturers of any radio device who enters any country which requires CE marking, have to use RED (Radio Equipment Directive 2014/53/EU) in their DoC.

This is applicable for all new products as well as for products that are currently being marketed and intended to be sold after this date. Products which DoCs are not updated by this date, should not be sold in the European Union.

It is very likely that any RED version of EN 301 893 will not be ready and will not be listed in the OJ on June 13, 2017. The version V2.0.7 of the standard is still in review process and is scheduled to be published on July 8, 2017. The standard is expected to be listed on the Official Journal of the European Union on October 21, 2017.

With the absence of this product standard, there is a possibility that EN 301 893 V1.8.1 may be listed in the OJ with additional Adaptivity and Receiver Blocking requirements aligned with 301 893 V2.0.7 in order to presume compliance with RED until the new version of the standard is published.

Otherwise, after June 13, 2017, any 5 GHz radio device must have a Notified Body Opinion/Type Examination Certificate in order to presume compliance with the Article 3.2 – essential requirements of Directive 2014/53/EU – RED. Which means that, overwhelming number of products on the market will require Notified Body Opinion.

The Notified bodies also have to follow Article 3.2 of RED in their assessments and will ask for evidence of presumption of conformity which will include Adaptivity and Receiver Blocking tests.

Our recommendation to the manufacturers is to schedule the tests for the new requirements as soon as possible since the test methods are significantly different.

Some of the major changes are:

  1. Adaptivity has 3 different mandatory Interference signal type (AWGN, OFDM and LTE). Medium Access test methods have changed significantly. There are new procedures for Frame Based (other than 802.11) devices.
  2. The Receiver Blocking requirement is a new performance test and unconditionally applicable to all radio equipment.

Please contact us at sales@nts.com or call 800-270-2516 for additional details and how to test your product and update test reports for Radio Equipment Directive.

X-Ray Computed Tomography Scanning & Composite Materials

X-ray inspection technology has come a long way over the past several decades. Since its inception in the 1970s, x-ray computed tomography, or CT scanning, has completely revolutionized medical diagnostic practices. In the 1980s, we saw the introduction of micro-focus x-ray technology, which had large implications for non-destructive testing in the industrial and scientific communities. It wasn’t however, until the new millennium that improvements in x-ray detection technology and computing power enabled commercially-viable micro-focus x-ray CT scanning.

With micro-focus CT scanning, data can be captured at incredibly high resolution, sometimes even at the sub-micron level. This makes CT scanning an extremely valuable tool in materials research, especially when analyzing composite materials and their internal structures. The raw scan data, which is usually several gigabytes (20 GB+), can be rendered in 3D and even numerically analyzed. The image below shows a 3D rendering of a small section of a carbon-epoxy structure captured at approximately a 4 micron resolution.

In this particular sample, a small composite block, the x-ray and imaging settings were optimized to enhance the contrast between the carbon fibers and epoxy resin. This enabled us to virtually segment and remove the resin material in order to expose the fiber structure. This data can be extremely valuable in evaluating structural properties of materials and different manufacturing processes. There are even software tools commercially available today that can numerically evaluate fiber consistency and orientation over an entire structure.

X-ray CT scanning is a very versatile process that can be performed on many different materials and even at different stages of a manufacturing process. The images above, show a high-resolution CT scan of a prepreg composite that has not yet been fully cured. In the image on the left (a single cross section), the brighter areas are the uncured resin material, and small openings and voids can be seen inside. These can also be numerically analyzed to provide far more data, including fiber volume fraction, both locally, and over a larger area.

Even on the more “macro” scale, micro-CT can be a very powerful tool in structural and failure analysis. Small defects such as porosity and thin delaminations can be visualized with high resolution images. Failure modes can be spotted and easily identified in even the most complex of structures. The image above shows a cross section image from a high-load bearing structure that failed during mechanical load testing. The origins and full extent of the failure can be studied without the use of any destructive techniques that may compromise the sample and data.

There are many applications of x-ray CT scanning in composite materials, and the list is rapidly growing. This type of testing has proven to be very beneficial in identifying damage and failure modes that previously had gone undetected, and has also provided the benefit of avoiding, often time-consuming, destructive analysis.

NTS Chesapeake operates one of the most powerful, high-resolution CT systems in use today. A large walk-in 450kV micro-focus system enables large objects (up to 37 inches in diameter) to be imaged with extremely high resolution. This system, combined with NTS’s other x-ray capabilities and state-of-the-art processing and visualization tools, allows this technology to solve numerous problems spanning many different industries.


Changes for Medical Equipment IEC 60601-1

UL 60601-1 and CAN/CSA C22.2 No. 60601-1

With the publication of the fourth edition of IEC 60601-1-2 [1] and its European equivalent, EN 60601-1-2 [2] being listed in the Official Journal, the EMC requirements for medical electronic devices changed. Products that will remain in production after the mandatory effective date of December 31, 2018 may require redesign to comply with the requirements of the fourth edition. Changes in design will also affect the FDA approval. Even if no changes are required, testing will need to be performed to assess the product’s performance in light of the expanded scope of testing of this new edition for the EU. There is no grandfathering of equipment that was assessed using the third edition of the standard in the EU. A presumption of conformity with the essential requirements of the Medical Device Directive (MDD) may only be assumed if the new edition is employed after the transition date. For the sake of brevity, whenever I refer to the standard, I am talking about the fourth edition of IEC 60601-1-2 and EN 60601-1-2.

Test Requirements: Emissions

The emissions requirements are found in Table 2 of the standard and cover conducted and radiated emissions using the limits and methods of CISPR 11, harmonic distortion using IEC 61000-3-2 and voltage fluctuations and flicker using IEC 61000-3-3. The application of IEC 61000-3-2 and IEC 61000-3-3 depends on the use environment. Different requirements may be necessary based on other uses, such as in transportation.

Test Requirements: Immunity

Performance Requirements

As you read the standard, you eventually get to the section on immunity requirements for ME equipment and systems. The test levels to be used are described in the standard for two types of environments. Use of higher or lower values may be used depending on the outcome of the risk management process.

At first glance, you may decide that degradations of performance are not allowed during the tests and that your product will not be able to meet a performance criteria without a significant redesign. However, as stated, the intent of this section is to describe these degradations in light of the Essential Performance and Basic Safety of the product being tested. The product is allowed to exhibit degradations that do not affect Essential Performance and safety during the tests.

Basic Safety and Essential Performance

What are Basic Safety and Essential Performance? These are defined terms in the standard IEC 60601-1. Basic Safety is “freedom from unacceptable risk directly caused by physical hazards when ME equipment is used under normal condition and single fault condition.” Essential Performance is “performance necessary to achieve freedom from unacceptable risk.” According to the standard, a risk management process shall be used to identify risks from electromagnetic disturbances in addition to any other risks.” Annex F provides additional guidance for including the risks from electromagnetic disturbances in the risk management process described in ISO 14971. The risk management report produced by the process provides the description of pass fail criteria for each function of the product and how the basic safety and essential performance will be monitored during each immunity test. This information is incorporated in the EMC test plan. This test plan is required prior to starting any EMC testing. An example is provided in Annex G of the standard.

The implication here is that you should perform a risk analysis (see Annex F of the standard for more details) prior to establishing the compliance criteria to avoid the need to perform more tests against more stringent criteria. Depending on the class of device as determined from Annex I of the medical device directive, a notified body will likely need to be consulted in determining the performance criteria to apply based on the risk analysis. The establishing of the performance criteria is crucial to evaluating the observations made of product operation during immunity tests and in determining the methods used to monitor the product. The risk analysis must account for all manners of use of the product. After assessing all the risks and determining the residual risk level, you enumerate the compliance criteria. Examples of criteria can be found in Annex I of the standard.


Now that you have established the compliance criteria you will use during the immunity tests, you are ready to test. Not so fast. The standard requires a completed test plan be prepared prior to the start of formal testing. The recommended content of the test plan is given in Annex G of the standard. The standard includes the normal set of immunity tests that are to be applied and describes test levels for special environments in Annex E. The tests are the same tests that are applied for other products such as radio equipment, networking equipment and information technology equipment except that the standard incorporates some specific test application guidance notes that require special consideration. Tables 4 through 8 list the immunity tests applicable to medical devices and the basic levels for both professional healthcare facility and home healthcare environments.

The list may include additional tests and the test specification column may change based on the type of equipment to be evaluated and particular standard that would therefore apply. It is beyond the scope of this paper to present the appropriate specifications for all medical devices. However, some examples can serve to illustrate the point. EN 60601-2-24, particular to infusion pumps, modifies the test specifications: radiated immunity test level changes to 10 V/m even if the product is for professional healthcare environments; magnetic immunity test level increases to 400 A/m. EN 60601-2-10, particular to nerve stimulators, adds that patient leads are to be placed in saline solution during testing. EN 60601-2-2, particular to HF surgical equipment, modifies the compliance criteria and the emissions test configuration.

To evaluate the DFS functions of a system the regulatory standards describe waveforms to be used when evaluating DFS. These waveforms are defined in terms of the number of pulses, the pulse width and the pulse repetition frequency (or period) for the radar signal. The pulses may be modulated with an FM chirp, and may contain pulses of different widths and different periods.  Manufacturers should always bear in mind that their radar detection algorithms should be designed to detect all radar systems.

Table 1: Immunity Tests
Environmental Phenomena Test Specification Test Setup
Electrostatic Discharge ±8kV (Contact)

±2, 4, 8, 15kV (Air)

EN 61000-4-2
RF Fields 80 – 2700 MHz

3V/m (professional healthcare facilities) or 10V/m (home use)

80% AM, 1 kHz

EN 61000-4-3
RF Proximity fields Various frequencies up to 28 V/m EN 61000-4-3
Fast transients



5/50ns, 100 kHz

±2.0 kV

±1.0 kV

EN 61000-4-4

Line to PE

Line to Line

Outdoor SIP/SOP


±0.5, 1.0 & 2.0kV

±0.5 & 1.0 kV

± 2 kV line to ground

EN 61000-4-5
RF Voltage (Conducted Immunity) 0.15 – 80 MHz

3V (6V in some frequency ranges)

80% AM, 1 kHz

EN 61000-4-6
Magnetic Fields* 50 Hz


EN 61000-4-8
Voltage Dips 100%, 0.5 cycles at various phase angles

100%, 1 cycle

30%, 25/30 cycles

EN 61000-4-11
Voltage Interruption 100% for 250/300 cycles EN 61000-4-11
*Applies only if the product has magnetically sensitive components or circuity


The standard has higher test levels for ESD and magnetic field immunity, magnetic field immunity may not be needed, additional RF field immunity requirements with potentially higher levels and additional VDI requirements compared to the previous edition. It also makes clear the need for a test plan prior to testing. Depending on the product, the test plan may need to include other tests or test levels that will also need to be evaluated based on the intended use of the product.

Basic Immunity Test Modifiers

For some of the immunity tests, the standard specifies modifications to the methods of the basic standards listed in table 1 above.

For example:

The dwell time at each frequency step for conducted and radiated immunity must be set to allow the product to be fully evaluated at each step. Dwell times exceeding 15 seconds are not uncommon.

Electrical fast transient tests are not performed on patient cables.

During conducted emissions, electrical fast transient/burst and conducted immunity tests, patient coupled parts shall be terminated with artificial hands.

CDNs shall not be used for conducted immunity tests on patient leads.

Power input voltage and frequency are specified for each test in Table 1 of the standard. In most cases, the tests are performed at one voltage and one frequency from the ranges of voltage and frequency for which the product is rated. Voltage dips and short interruption tests shall be performed at the minimum and maximum rated voltages if the product has rated voltage range ≥ 25% of the minimum rated voltage.

Product Information

Assuming that you have performed all of the appropriate emissions and immunity tests using the compliance criteria specified in the test plan with acceptable results, the requirements of the standard are still not yet fulfilled. The standard requires information about EMC to be included in the instructions furnished to the user. These can be found in Clause 5. The tables of information there were part of the third edition of the standard are not included in the fourth edition.

The instructions shall also provide technical information such as compliance information for each test and test levels for immunity. The justification for using the levels other than described in the standard shall be provided in the instructions. Instructions necessary for maintaining BASIC SAFETY and ESSENTIAL PERFORMANCE with regard to electromagnetic disturbances shall also be provided.

Radio Functions in Medical Devices

If a radio is provided with the product either internally or as a separate unit, the radio part of the device or system may only need approval against the applicable radio standards. However, if the function of the radio affects the essential performance of the system, then the radio and medical device both must be evaluated for immunity using the medical equipment standard.

The emissions of the radio part must comply with the medical equipment standard except in the dedicated transmission band. This means that spurious emissions of the radio must meet the CISPR 11 limits, which in most cases are more restrictive than the spurious emissions limits for the radio device.


The new edition of EN 60601-1-2 presents many challenges to manufacturers. From the beginning of the design process, manufacturers are encouraged to seek assistance from test labs and certification agencies to understand the provisions of EN 60601-1-2 as they apply to their specific product.


[1] IEC 60601-1-2:2014, International Standard for Medical electric equipment – Part 1-2: General requirements for basic safety – Collateral standard: Electromagnetic compatibility – Requirements and tests.

[2] EN 60601-1-2:2015, European Standard for Medical electric equipment – Part 1-2: General requirements for basic safety – Collateral standard: Electromagnetic compatibility – Requirements and tests.

Upcoming Changes for Wireless Equipment in the 2.4 GHz Band EN 300 328

By Deniz Demirci, Senior Wireless/EMC Engineer at NTS Silicon Valley

EN 300 328 V2.1.1 was harmonized and listed in the Official Journal of the European Union under Directive 2014/53/EU for RED (Radio Equipment Directive) on January 13, 2017. This version of the standard covers the essential requirements of article 3.2 of RED for 2.4 GHz ISM band WiFi, Bluetooth and other Wideband transceivers.

Manufacturers of these type of equipment can still use R&TTE Directive 1999/5/EC (Radio and Telecommunication Directive) and it’s harmonized standard EN 300 238 V1.9.1 in their Declaration of Conformities (DoC) until June 13, 2017.

After this date, manufacturers of any radio device who enters any country which requires CE marking, have to use RED (Radio Equipment Directive 2014/53/EU) in their DoC.

This is applicable for all new products as well as for products that are currently being marketed and intended to be sold after this date. Products which DoCs are not updated by this date, should not be sold in the European Union.

Manufacturers should follow EN 300 328 V2.1.1 requirements and update their test reports for their current products as soon as possible since there is significant change in the essential requirements;

  • The Receiver Blocking Requirement is unconditionally applicable to all radio equipment regardless of receiver category or adaptivity capability. This is a major change from the previous version of the standard.

Since the Receiver Blocking was conditionally applicable to the adaptive equipment only and the test methods as well as the performance criteria were different, most products may have never been evaluated for this requirement before.

Note: After June 13, 2017, any radio device which the standards are not yet harmonized and listed in the Official Journal of the European Union, must have a Notified Body Opinion/Type Examination Certificate in order to presume compliance with the essential requirements in Article 3.2 of Directive 2014/53/EU – RED.

For more details and information on how to update test reports for the Radio Equipment Directive, other specification interoperability scenarios or test, design and engineering help is available by contacting NTS at 800-270-2516 or emailing sales@nts.com.

Radio Equipment Directive (RED) Transition Time Coming Soon

Is your organization ready for the transition to the Radio Equipment Directive (RED)? RED must be employed for all products included in its scope and not yet placed on the EU market after June 12, 2017. Even products that were already being sold as compliant with the R&TTE directive must comply with the RED to continue to be placed on the market after this date.

The EU Commission has continued to add standards to the harmonized standards list, visit the EU Commission website to review the latest updates, as of March 10, 2017.

To learn more, visit our RED page or contact us today!

TorBots 1197 Robot Reveal

The TorBots 1197 revealed their latest robot creation on Friday, March 3rd at South High School in Torrance, California. The six week build period came to a close and students from all grade levels gathered to not only reveal their robot but to thank everyone that made it possible.

Throughout the year the TorBots team competes in a series of “games” where they must build a robot that is capable of doing certain tasks. This year’s game is titled FIRST Steamworks where the robot must collect gears, fuel (softball-sized whiffle balls) and construct a “flying” device. Not only does it have to collect those items but it must also have the capability to hoist itself up to “fly” away with the final product. Here’s a preview of what the students were able to construct:

This is all made possible by a group of mentors, sponsors and charitable donations. Mentors are either teachers or staff at the school, volunteers within the local engineering community or alumni of the TorBots program that simply want to lend a helping hand. Sponsors help, along with fundraisers, send the team to regional, state and national competitions. Donations can range anywhere from unused equipment, safety glasses or financial donations to help keep the program alive and well.

Last summer NTS donated several testing machines from the LAX facility that would help the team test the durability of their robots, including the one to be used in the FIRST Steamworks competition. Along with the testing equipment, safety glasses were donated to maintain the high safety standard that NTS promotes at its own facilities. Equipment and safety glasses weren’t the only items donated by NTS, Jerry Shu, a Test Technician out of LAX, donated his time and knowledge to the team. As an alumni of the program Jerry knows exactly what it takes to teach the students about mechanics but also understands what it takes to inspire young minds to come up with such amazing inventions.

An opportunity to combine a formal education and real-world skills is presented to these students and is made possible through various donations of time, equipment and money. Students fabricate frames, program software, engineer gears and mechanisms and learn to come together towards one common goal to succeed at the task at hand.

The TorBots 1197 team will be participating in their first Los Angeles Regional event March 23rd – March 26th at California State University of Long Beach. For more information on the First Robotics Competition click here.

For more information on the TorBots 1197 FIRST Steamworks competition please click here.

Taiwan: Emissions Testing for Information Technology Equipment, CNS 13438 Requirements

by Wayne Fisher, EMC Lab Manager,
NTS Silicon Valley

Manufacturers of Information Technology Equipment (ITE) intended for sale in Taiwan should take note that as of October 1, 2010 EMC testing requirements under emissions standard CNS 13438 have changed.

The Bureau of Standards, Metrology and Inspection (BSMI) requires radiated emissions both from 30MHz to 1GHz and conditions requiring testing upwards of 6GHz. Additionally, con­ducted emissions on telecommunication ports are required on all networking ports (IE: Ethernet).

The radiated emissions above 1GHz requirements are based on Amendment 1:2005 of CISPR 22:2005, which means testing is performed in a free space facility.

  • If the highest internal frequency source of the device under test is less than 108MHz radiated measurements are only performed up to 1000MHz.
  • If the device has an internal frequency source between 108MHz and 500MHz, the measurement shall only be made up to 2GHz.
  • If the frequency is between 500MHz and 1GHz, the measurement shall be only up to 5GHz.
  • If the frequency of the internal sources is above 1GHz the measurement shall be up to 5 times the highest frequency or 6GHz, whichever is less.

The Conducted Emissions on Telecommunication Ports requirements are the same as those in CISPR 22 with multi-speed ports operating at their highest data rate. Where there are many electrically identical telecommunication ports, multiple pre-scans may be required to determine the ‘worst case’ port for final evaluation.

The testing is performed with the device under test operating from line voltages consistent with Taiwan. For Class A devices, testing must be performed at both 110VAC and 220VAC or 230VAC, 60Hz. For Class B devices, testing need only be performed at 110VAC, 60Hz.

Products that were approved prior to October 1, 2010 will be accepted into the Taiwan market until their certificate is subject to renewal or if changes have been made to a product that needs re-certification after that date. At that point in time, products will need to demonstrate compliance with the new requirements.

New rules currently under draft may be implemented this year have indicated that all approvals must adhere to RoHS rules otherwise certificates will expire at the end of this year. Evidence of RoHS certification for the EU will be accepted by Taiwan towards this requirement.

Contact us at sales@nts.com or call 800-270-2516 to know more about the steps you need to take to ensure compliance of your ITE products with the requirements of Taiwan.