Interview Questions for IEC 61724-1 Compliance Testing

IEC 61724-1, “Electromagnetic compatibility (EMC) – Part 1: General requirements and test methods,” defines the general requirements and test methods for assessing the electromagnetic compatibility of industrial-process measurement and control equipment. In essence, it ensures that this equipment doesn’t cause harmful interference to other devices, and conversely, that it can withstand interference from its environment without malfunctioning. Its scope covers a wide range of equipment used in industrial settings, encompassing everything from sensors and actuators to programmable logic controllers (PLCs) and other crucial components within industrial automation systems.

Think of it like this: a busy factory floor is a noisy electromagnetic environment. IEC 61724-1 sets the rules to ensure all the ‘instruments’ within that environment can communicate effectively without causing issues (like a sudden machine stop due to electromagnetic interference), all while tolerating the existing ‘noise’ levels present in that environment.

IEC 61724-1 specifies several immunity tests to evaluate how well equipment withstands electromagnetic disturbances. These tests simulate real-world interference scenarios to ensure the equipment’s robustness. Key immunity tests include:

• Conducted Disturbances: These tests evaluate the equipment’s resistance to interference injected directly into its power supply lines and signal lines. This includes tests for burst, surge, dips, and variations in voltage levels.
• Radiated Disturbances: These tests assess the equipment’s resilience to electromagnetic fields radiated from nearby sources. The equipment is exposed to electromagnetic fields across various frequencies and field strengths.
• Electrostatic Discharge (ESD): This crucial test examines the equipment’s ability to withstand the sudden discharge of static electricity, often caused by human contact.
• Fast Transient/Burst Immunity: This test evaluates how well the equipment functions when exposed to short, high-amplitude voltage spikes, commonly occurring on power lines.

The specific tests and levels applied depend on the equipment’s intended application and classification within the standard.

The key difference lies in how the interference is applied. Conducted emissions refer to interference that travels along cables or wires connected to the equipment. Think of it like noise traveling through electrical wires. Radiated emissions, on the other hand, are electromagnetic waves that propagate through the air, similar to radio waves. This means radiated emissions tests assess the electromagnetic field emitted by the equipment itself, whereas conducted emissions tests measure the interference injected into or conducted from the equipment’s power and signal lines.

Imagine a radio: The radio’s own emissions (radiated) are the radio waves it transmits. However, if the radio’s power cord generates noise (conducted), that noise could interfere with other equipment plugged into the same power outlet.

Determining appropriate test levels for IEC 61724-1 compliance is crucial and depends on several factors:

• Equipment Category: The standard defines different categories of industrial equipment, each with specified immunity requirements. This categorization is based on the equipment’s role and susceptibility to interference.
• Environmental Conditions: The anticipated operating environment significantly influences the test levels. A harsh industrial environment will require higher immunity levels compared to a controlled lab setting.
• Manufacturer’s Specifications: Manufacturers might specify higher immunity levels than those mandated by the standard to ensure a product’s robustness in challenging conditions.

The standard provides tables and guidelines to determine the appropriate test levels based on these factors. Often, a risk assessment is performed to justify the chosen levels. For example, a safety-critical component in a hazardous environment would require substantially stricter test levels.

The limit values defined in IEC 61724-1 are critical because they represent the maximum permissible levels of interference that the equipment can emit (emissions) and withstand (immunity) while still functioning correctly. These limits are based on ensuring that the equipment doesn’t cause harmful interference to other devices in its environment, and it can tolerate the expected levels of interference without failure.

Exceeding these limits signifies a failure to meet the standard and could lead to product recalls, regulatory issues, and potential damage to other equipment or even safety hazards. These values are carefully determined to balance the need for robust equipment with practical implementation challenges.

A Line Impedance Stabilization Network (LISN) is a crucial component in EMC testing, especially for conducted emissions measurements. Its primary function is to create a well-defined impedance between the Equipment Under Test (EUT) and the power mains. This ensures consistent and accurate measurement of conducted emissions by minimizing reflections and variations in impedance, which could otherwise distort the measurement results. It simulates the typical impedance seen by the equipment in a real-world installation.

Think of it as a controlled interface: It ensures the noise emitted by the equipment is measured accurately, independent of the specific wiring in the test setup. Without a LISN, the measurements would be unreliable and difficult to interpret.

Troubleshooting an EMC failure during testing requires a systematic approach:

1. Repeat the Test: First, repeat the failing test to confirm the issue isn’t a fluke.
2. Analyze the Failure Mode: Determine the precise nature of the failure. Is it a functional failure, a performance degradation, or a safety hazard?
3. Examine Test Setup: Check the entire test setup for any errors, including proper cabling, LISN connections, and correct instrumentation settings. A simple error can lead to a false failure.
4. Inspect the EUT: Thoroughly examine the EUT for any obvious physical issues or component failures that could contribute to the EMC problem. This might include loose connections, damaged components, or incorrect wiring.
5. Systematic Troubleshooting: Use techniques such as signal tracing, probing, and spectrum analysis to isolate the source of the interference. This often involves examining various parts of the circuit to identify where the noise is generated or picked up.
6. Shielding and Filtering: If the source is identified, implementing shielding (to isolate the noise source) or adding filters (to attenuate the specific frequency of the noise) might be necessary solutions.
7. Software Modifications: If the source of the issue lies in the software, appropriate debugging and modifications might be needed.

Documenting each step and finding the root cause is key to resolving the EMC issue permanently. It’s often an iterative process requiring careful observation and analysis.

Interpreting an EMC test report requires a thorough understanding of the standards and the equipment under test. The report should clearly state whether the Equipment Under Test (EUT) met the specified limits for emissions and immunity. Let’s break it down:

• Limits: The report will show the limits defined in the relevant IEC 61724-1 standard (or other applicable standards) for conducted and radiated emissions and immunity. These limits are frequency-dependent and vary based on the EUT’s classification.
• Measured Values: The report presents the measured emissions and immunity levels of the EUT at various frequencies. These values are typically plotted graphically.
• Compliance: The most crucial part! The report will explicitly state whether the measured values are within the specified limits. If a value exceeds the limit, it’s a non-compliance. The report may also detail the margin by which the limit is exceeded.
• Test Methods: The report should detail the specific test methods used, ensuring they align with the applicable standards. Variations in methods can influence results.
• Uncertainty: Every measurement has an associated uncertainty. The report should state the measurement uncertainty, reflecting the reliability of the results. A higher uncertainty means less confidence in the results.

For example, a report might show that the EUT’s radiated emissions at 100MHz exceeded the limit by 3dB. This indicates a problem that needs to be addressed, potentially by redesigning or shielding components.

Proper grounding and shielding are paramount in EMC testing to minimize external interference and ensure accurate and reliable results. Imagine trying to measure a faint whisper in a hurricane – that’s what it’s like without effective grounding and shielding.

• Grounding: A robust ground connection creates a low-impedance path for unwanted currents to flow to earth, preventing them from influencing the measurement. Grounding ensures that the EUT and the test equipment are at the same potential, eliminating ground loops that can introduce significant noise. A good grounding system uses thick, low-impedance wires, ensuring good contact at all connection points.
• Shielding: Shielding helps prevent electromagnetic fields from entering or leaving the test environment. Shielding enclosures, made of conductive materials, effectively block electromagnetic radiation. The effectiveness of shielding depends on the shielding material, its thickness, and the frequency of the radiation. Effective shielding prevents external noise from affecting the measurement and prevents the EUT’s emissions from interfering with the test equipment.

Poor grounding can lead to false readings, while inadequate shielding can allow external interference to contaminate the measurement, leading to inaccurate results and potentially a faulty declaration of compliance or non-compliance.

Electromagnetic interference (EMI) sources are ubiquitous in our electronic environment. They range from intentional emitters to unintended byproducts of electrical equipment operation:

• Switching Power Supplies: These are a major culprit, generating high-frequency noise due to their switching action.
• Motors and Drives: Brushed motors generate significant EMI due to the commutation process. Variable-frequency drives (VFDs) also produce considerable noise.
• Digital Circuits: High-speed digital logic circuits generate fast-rising edges, which radiate electromagnetic energy.
• Radio Transmitters: Intentional emitters, but their signals can interfere with other devices if not properly managed.
• Power Lines: High-voltage power lines carry substantial currents, generating magnetic fields that can couple into nearby electronics.
• External Sources: Lightning strikes, electrostatic discharge (ESD), and even radio and TV broadcast signals can all contribute to EMI.

Identifying these sources is the first step toward mitigating their effects and ensuring compliance with EMC standards.

Mitigating EMI requires a multi-pronged approach, incorporating design considerations and physical modifications. The best approach often involves a combination of techniques:

• Shielding: Enclosing sensitive components or the entire EUT in a conductive enclosure to block electromagnetic fields.
• Filtering: Using filters (e.g., LC filters) to attenuate specific frequency ranges of noise on power lines and signal lines.
• Grounding: Establishing a robust ground plane and ensuring proper grounding of all components to minimize ground loops and reduce noise propagation.
• Cable Management: Using shielded cables and properly routing cables to minimize unwanted coupling between circuits.
• Layout Optimization: Careful design of PCB layout can significantly reduce EMI. For example, keeping sensitive analog circuits far away from noisy digital circuits.
• Component Selection: Choosing components with low EMI characteristics is essential. This includes using shielded transformers and selecting components with low radiated emissions.
• Software Techniques: In digital systems, software techniques like edge-rate control can reduce the intensity of EMI generated by fast switching.

For instance, if a motor is producing excessive EMI, shielding the motor or employing EMI filters on its power supply lines could be effective solutions.

Common mode and differential mode noise are two distinct types of noise that propagate differently and require different mitigation strategies. Think of it like two different types of waves:

• Differential Mode Noise: This is the noise voltage between two signal lines. It’s the difference in potential between the two wires. Imagine a signal travelling down two wires; differential mode noise is the variation in the signal amplitude *between* the wires. It’s commonly seen in signal transmission.
• Common Mode Noise: This is the noise voltage present on both signal lines *relative to ground*. Both lines have the same noise voltage relative to earth. Imagine both wires having the same unwanted voltage fluctuation; that’s common mode noise. It’s often a problem due to ground loops or imbalances in the system.

Mitigation strategies differ: Differential mode noise is addressed using differential amplifiers and balanced lines, while common mode noise requires techniques like common mode chokes and proper grounding.

The test setup varies significantly depending on the type and size of the equipment under test (EUT), as well as the specific EMC standard being followed. The variations account for differences in operating characteristics and potential interference sources.

• Size and Type of EUT: Larger EUTs require larger test chambers and different antenna configurations compared to small devices. For instance, testing a large industrial machine would need a significantly different setup from testing a small consumer electronic device.
• Conducted vs. Radiated Emissions: Testing conducted emissions (noise on power lines) involves connecting LISN (Line Impedance Stabilization Networks) to measure current and voltage on power lines; while radiated emissions (radio waves) requires an open-area test site (OATS) or a shielded chamber and specialized antennas to capture radiated energy.
• Frequency Range: The frequencies of interest define the test bandwidth and require different instrumentation and test probes. For example, testing high-frequency devices may require different antennas and measurement equipment than testing low-frequency devices.
• Immunity Tests: Immunity tests expose the EUT to various forms of electromagnetic fields (e.g., conducted, radiated, electrostatic discharge). The specific test setup depends on the type of immunity test, with varying signal generators, field strengths, and coupling methods.

It’s critical to ensure that the test setup accurately reflects the EUT’s operational environment to ensure meaningful and relevant results.

Near-field and far-field measurements refer to different regions surrounding an electromagnetic source, influencing how the electromagnetic field is measured:

• Near Field: This region is close to the radiating source, where the electromagnetic field is complex and has reactive components. The electric and magnetic fields are not necessarily in phase, and the field strength varies rapidly with distance. Measurements in the near-field are often challenging and require specialized equipment and techniques.
• Far Field: This region is at a significant distance from the source, where the electromagnetic field is primarily a propagating wave. The electric and magnetic fields are in phase, and the field strength decreases inversely proportional to the distance. Far-field measurements are more straightforward and commonly used for compliance testing.

The transition distance between near-field and far-field depends on the physical size of the radiating source and the frequency. Generally, the far-field begins at a distance of approximately λ/2π (where λ is the wavelength) from the source. Near-field measurements are sometimes important for characterizing antenna behaviour, but far-field is usually the primary focus of EMC compliance testing as this is the field that impacts surrounding devices.

EMC pre-compliance testing is crucial for identifying potential EMC issues before submitting your product for official certification. It’s like a pre-flight check for your device’s electromagnetic compatibility. The goal is to find and fix problems early, saving time and money in the long run. Key considerations include:

• Selecting the right test equipment: This ensures accurate measurements and reliable results. You need equipment calibrated to the relevant standards.
• Understanding the applicable standards: IEC 61724-1 itself specifies certain emission and immunity limits. You also need to know any other specific standards that apply to your product category.
• Creating a proper test setup: This involves using the right test cables, grounding techniques, and shielding to minimize external interference and obtain reliable measurements. Incorrect setup can lead to erroneous results.
• Systematic troubleshooting: This involves a methodical approach to identifying the sources of emissions and susceptibility issues. This might involve checking for grounding issues, component placement, PCB design, or even the choice of materials.
• Documentation: Maintaining a comprehensive record of all tests, measurements, and corrective actions taken. This is essential for demonstrating compliance later.

For example, a poorly designed power supply might radiate significant noise, exceeding the limits. Pre-compliance testing helps you identify such problems and implement countermeasures, such as adding EMI filters, before official testing.

EMC filters are essential components in mitigating electromagnetic emissions. They act as barriers, preventing unwanted electromagnetic energy from radiating into the environment. Think of them as noise suppressors for your electrical signals. They work by attenuating (reducing) the amplitude of unwanted frequencies, effectively cleaning up the electromagnetic emissions from the device.

Filters achieve this by using various passive components like inductors, capacitors, and sometimes ferrite beads. These components are arranged in specific configurations (e.g., LC filters, pi filters) to create a frequency-dependent impedance, blocking or diverting unwanted noise signals while allowing the desired signals to pass through.

Several types of EMC filters exist, each suited for different applications:

• Common Mode Chokes: These suppress common-mode noise – noise that travels on both the hot and neutral wires of a power line, often related to ground loops. They’re essential in power entry circuits.
• Differential Mode Chokes: These filters suppress differential-mode noise – noise present between the hot and neutral lines. They’re commonly used in signal lines and data interfaces.
• LC Filters (Inductor-Capacitor): These use inductors and capacitors in various configurations (pi-filters, T-filters) to provide broad frequency attenuation. They are very versatile and commonly used.
• Pi Filters: A type of LC filter with a capacitor at each end and an inductor in the middle, offering good attenuation over a wide range of frequencies.
• Ferrite Beads: Small, cylindrical components made of ferrite material. They are effective at attenuating high-frequency noise but have a relatively narrow bandwidth.

For instance, a common-mode choke would be used in a power supply to reduce noise on the power lines, whereas a differential-mode choke would be used to filter noise on a high-speed data line. The choice depends on the type of noise and the frequency range you need to suppress.

Verifying the effectiveness of EMC countermeasures is crucial to ensure compliance. This is done through a combination of measurements and analysis.

• Repeat pre-compliance testing: After implementing a countermeasure (like adding an EMI filter), repeat the original tests to see if the emissions or susceptibility have improved. Comparing before-and-after results clearly shows the impact.
• Analyze measurement data: Carefully examine the measurements to identify if the implemented countermeasures have reduced emissions to below the required limits. Document everything.
• Use specialized analysis tools: Software tools can be used to analyze the impedance or scattering parameters (S-parameters) of filters or other countermeasures to verify their effectiveness across the frequency range.
• Consider worst-case scenarios: Verify that the countermeasures remain effective under various operating conditions (temperature, humidity, load variations).

For example, if a high-frequency emission is too high, adding a ferrite bead might be enough to reduce it below the limit. Repeat testing confirms this.

IEC 61724-1 compliance reporting requires comprehensive documentation. The report must clearly demonstrate that the equipment meets the specified emission and immunity limits. The following are typically included:

• Test setup description: Detailed diagrams and descriptions of the test environment, equipment used, and test procedures followed.
• Measurement results: All measurement data, including graphs and tables, clearly showing the emission and immunity levels.
• Compliance statement: A clear statement declaring whether the equipment meets the requirements of IEC 61724-1 and relevant standards.
• Corrective actions (if any): Detailed description of any modifications or countermeasures implemented to address non-compliance issues and the results obtained after implementation.
• Calibration certificates: Proof of calibration for all measuring instruments used.
• Test laboratory accreditation: If testing is done by an external lab, documentation confirming the laboratory’s accreditation.

A well-structured report ensures transparency and traceability, making it easier to verify the compliance status of the equipment.

EMC immunity testing assesses a device’s ability to withstand various electromagnetic disturbances without malfunction. It’s about ensuring your device can tolerate the electromagnetic environment it will operate in, much like ensuring a car’s robustness to unexpected bumps in the road. The goal is to evaluate whether the equipment will function properly despite exposure to external electromagnetic fields.

This testing involves subjecting the equipment to controlled levels of electromagnetic interference (EMI) simulating real-world scenarios, such as electrical fast transients or radio frequency fields. The response of the equipment is carefully observed to identify any malfunctions or performance degradation.

IEC 61724-1 specifies various immunity test methods, including:

• Electrostatic Discharge (ESD): Simulates the discharge of static electricity, often through contact or air discharge. It tests the device’s robustness to static shocks.
• Electrical Fast Transients/Bursts (EFT/Burst): Simulates fast transients and bursts in the power lines, a common occurrence in many electrical environments.
• Surge Immunity: Evaluates the device’s ability to withstand high-voltage surges, often coming from lightning strikes or power line switching.
• Conducted Disturbances: Tests the device’s resistance to conducted noise on power lines and signal lines.
• Radiated Immunity: Evaluates the device’s response to radiated electromagnetic fields, such as those from nearby radio transmitters or other electronic devices.

Each method has specific test levels and procedures defined by the standard, and the appropriate tests depend on the device’s intended application and operating environment.

Selecting the right test equipment for IEC 61724-1 compliance testing is crucial for accurate and reliable results. It involves considering several factors, primarily the specific requirements of the standard and the characteristics of the device under test (DUT).

• Frequency Range: The equipment must cover the frequency range specified in IEC 61724-1, typically ranging from 9 kHz to 400 GHz, depending on the specific emission limits.
• Test Type: Different tests require different equipment. For example, radiated emission testing needs an anechoic chamber, spectrum analyzer, and a pre-amplifier, while conducted emission testing requires a line impedance stabilization network (LISN) and a spectrum analyzer.
• Measurement Uncertainty: The equipment’s measurement uncertainty should be significantly lower than the specified emission limits to ensure accurate results. A higher-quality instrument will usually provide lower uncertainty.
• Calibration: The equipment must be calibrated regularly to a traceable standard, usually by a National Metrology Institute or an accredited calibration laboratory. Calibration certificates are essential for demonstrating compliance.
• Software Compatibility: Ensure the test equipment’s software is compatible with the required analysis and reporting software needed for the documentation process.

For instance, if testing a low-power device for radiated emissions, you might select a spectrum analyzer with a wide dynamic range and a pre-amplifier for sensitivity, coupled with a smaller, cost-effective anechoic chamber. However, testing a high-power device would require a larger chamber, a more robust spectrum analyzer and potentially additional shielding.

Calibration is the cornerstone of reliable EMC testing. It ensures that the test equipment provides accurate and traceable measurements. The procedures generally follow these steps:

1. Frequency Calibration: This involves verifying the accuracy of the frequency response of the equipment, often using a calibrated signal generator. Any deviations from the expected values need to be corrected or documented.
2. Amplitude Calibration: This ensures the accuracy of the amplitude measurements, typically using a calibrated signal attenuator or power meter. This process verifies the linearity of the receiver’s response over its dynamic range.
3. Time-domain Calibration (where applicable): For time-domain measurements, the calibration involves verifying the timing accuracy of the equipment, often using a pulse generator with a precise timing reference.
4. Traceability: All calibrations must be traceable to a national or international standard, typically through a calibration certificate issued by an accredited laboratory. This certificate establishes the equipment’s accuracy and reliability.
5. Documentation: Meticulous records of calibration procedures, results, and dates are essential for regulatory compliance and audit trails. These records demonstrate the validity and accuracy of the test results.

Think of calibration like getting your car’s speedometer checked; without regular calibration, you won’t be confident in the accuracy of your readings – and similarly, in EMC testing, inaccurate equipment leads to faulty results and potential non-compliance.

IEC 61724-1 compliance testing presents several challenges:

• Finding a suitable test site: Meeting the stringent environmental requirements of an anechoic chamber for radiated emissions can be difficult, particularly if you lack access to an in-house facility.
• Susceptibility to environmental factors: External electromagnetic interference (EMI) can affect measurements, necessitating thorough site characterization and potentially multiple test runs.
• Complex instrumentation: Setting up and operating the test equipment requires specialized expertise. Incorrect setup can lead to inaccurate results or even damage the equipment.
• Reproducibility of results: Achieving consistent results across different tests or test sites can be challenging. Minor changes in setup or the environment can significantly impact results.
• Meeting tight deadlines: Often, products have stringent release dates, putting pressure on testing procedures and requiring meticulous planning.
• High testing costs: Utilizing anechoic chambers and specialist equipment can be expensive, adding to the overall product development cost.

For example, I once encountered difficulties repeating radiated emission tests due to subtle changes in the DUT’s orientation within the anechoic chamber. Careful documentation of the setup and controlled environmental conditions were key to resolving the issue.

Handling non-compliance during testing requires a systematic approach:

1. Identify the source of non-compliance: A thorough investigation is needed to pinpoint the specific components or design aspects causing the emissions to exceed the limits. This often involves careful analysis of the test results and potentially detailed measurements on individual circuits.
2. Implement corrective actions: Based on the root cause analysis, corrective actions might include modifying the circuit design, adding filtering components, improving shielding, or changing the grounding scheme.
3. Retesting: After implementing corrective actions, the DUT must be retested to verify compliance. This iterative process of testing and refinement is common in EMC design.
4. Documentation: All corrective actions, retest results, and any deviations from the original test plan must be meticulously documented. This documentation is crucial for demonstrating compliance.
5. Consider alternative compliance methods: In some cases, demonstrating compliance might require exploring alternative testing methods or applying for regulatory exceptions.

A common scenario is finding excessive conducted emissions caused by a poorly designed power supply. Implementing a common-mode choke or adding additional filtering capacitors often resolves this issue.

My experience encompasses a wide range of EMC standards and regulations, including but not limited to:

• IEC 61000-4-x (immunity tests): I have extensive experience in testing equipment for immunity to various electromagnetic phenomena, such as surges, electrostatic discharge (ESD), and fast transients.
• CISPR standards (emissions): I’m proficient in conducting both radiated and conducted emission tests according to CISPR standards, which are widely used for evaluating the electromagnetic compatibility of IT equipment and other products.
• FCC regulations (United States): I’m familiar with the FCC’s regulations concerning electromagnetic compatibility, including the procedures for obtaining certifications.
• CE marking (European Union): I understand the requirements for CE marking related to EMC compliance, including the necessary testing and documentation.

My expertise isn’t limited to specific standards, but rather centers on understanding the underlying principles of EMC and adapting test strategies to meet varied regulatory requirements.

The electromagnetic spectrum is the range of all types of electromagnetic radiation. It spans from extremely low frequencies (ELF) to extremely high frequencies (EHF), encompassing various forms of radiation including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Understanding the spectrum is fundamental to EMC testing because different frequencies behave differently and affect various components in diverse ways. For instance, low-frequency emissions might couple through power lines, while high-frequency emissions might radiate more easily.

The spectrum is characterized by its frequency (or wavelength), which determines the energy and properties of the radiation. Higher frequencies correspond to shorter wavelengths and higher energy.

In EMC testing, we are particularly interested in the radio frequency (RF) portion of the spectrum, which is where many electronic devices operate and where interference is most likely to occur. Thorough knowledge of the electromagnetic spectrum is essential for designing and testing systems that operate reliably and without causing or receiving harmful interference.

Staying updated in the rapidly evolving field of EMC testing requires a multi-pronged approach:

• Regularly attending industry conferences and workshops: These events provide opportunities to learn about the latest advancements in testing techniques, instrumentation, and regulatory changes.
• Subscribing to relevant professional journals and publications: Publications such as IEEE EMC Transactions and other industry-specific magazines provide valuable insights into current research and developments.
• Participating in professional organizations: Membership in organizations like the IEEE EMC Society provides access to valuable resources, networking opportunities, and updates on standards revisions.
• Following regulatory agency updates: Closely monitoring changes issued by organizations like the FCC, CISPR, and other relevant bodies ensures compliance with the latest requirements.
• Maintaining a network of professional contacts: Networking with other EMC engineers and experts facilitates the exchange of knowledge and practical experience.

For example, I actively participate in online forums and attend webinars to stay abreast of any changes in international EMC standards. This proactive approach ensures I am always equipped with the latest knowledge and best practices.