Complying with CE for Telemetric Application

Telemetric applications, encompassing a wide range of devices that transmit data wirelessly over distances, are integral to numerous industries, including healthcare, industrial automation, and consumer electronics. As these devices become more prevalent, ensuring their compliance with European regulatory standards is crucial for market access and consumer safety.

The CE marking is a certification mark that indicates conformity with health, safety, and environmental protection standards for products sold within the European Economic Area (EEA). Achieving CE compliance for telemetric applications is not only a legal requirement but also a mark of quality and reliability, fostering trust among consumers and stakeholders.

This article provides a comprehensive guide for manufacturers and developers of telemetric devices to navigate the complexities of CE compliance. It covers the regulatory framework governing telemetric applications, including key directives such as the Radio Equipment Directive (RED), Electromagnetic Compatibility (EMC) Directive, and Low Voltage Directive (LVD). The step-by-step compliance process outlined in this blog will help ensure that telemetric products meet all necessary technical and safety requirements.

Key topics addressed include:

• Understanding the relevant EU regulations and harmonized standards for telemetric devices.
• Detailed compliance process from risk assessment to affixing the CE mark.
• Specific technical requirements and testing procedures necessary for compliance.
• Effective documentation practices, including the creation and maintenance of the Technical File and the EU Declaration of Conformity.
• Common challenges in achieving CE compliance and practical solutions to overcome them.

By following the guidance in this whitepaper, manufacturers can streamline their compliance efforts, reduce time-to-market, and ensure their telemetric devices are ready for the European market. This document serves as an essential resource for anyone involved in the development, production, or regulation of telemetric technologies, providing the knowledge and tools needed to achieve CE compliance effectively and efficiently.

1     Introduction

1.1.  Definition of Telemetric Application

Telemetric applications refer to the use of technology for remotely collecting and transmitting data over various distances. These applications are widely used in various fields such as healthcare for patient monitoring, industrial automation for machinery control, and consumer electronics for smart devices. Telemetric systems typically involve sensors, data transmission modules, and central processing units to analyze the received data.

1.2.  Brief Overview of the CE Marking

The CE marking is a certification mark that indicates that a product conforms to the relevant European health, safety, and environmental protection standards. The letters "CE" stand for "Conformité Européenne," which means "European Conformity." Products bearing the CE mark can be sold freely within the European Economic Area (EEA), making it a crucial requirement for manufacturers looking to access this market.

1.3.  Significance of CE Marking in the European Market

CE marking is not only a mandatory regulatory requirement for products sold in the EEA but also a symbol of quality and safety recognized globally. For telemetric applications, obtaining the CE mark ensures that the products meet stringent safety, health, and environmental protection standards, providing assurance to consumers and regulatory bodies. Compliance with CE marking helps manufacturers avoid legal repercussions, gain customer trust, and enhance their competitive edge in the European market.

By following the guidance provided in this white paper, stakeholders in the telemetric industry can navigate the complexities of CE compliance more effectively, ensuring that their products are both market-ready and aligned with European standards for safety and performance.

2   Regulatory Framework

2.1.  Overview of European Union Regulations

The European Union (EU) has established a comprehensive regulatory framework to ensure the safety, health, and environmental protection of products entering its market. This framework is crucial for maintaining high standards and protecting consumers and users across the EEA. CE marking is a key component of this framework, signifying that a product complies with all applicable EU directives and regulations.

2.2.  Key Directives Relevant to Telemetric Applications

Telemetric applications fall under several specific directives that address different aspects of safety, performance, and compatibility. The primary directives relevant to telemetric devices include:

2.2.1.      Electromagnetic Compatibility (EMC) Directive

The EMC Directive (2014/30/EU) aims to ensure that electrical and electronic equipment does not generate or is not affected by electromagnetic disturbance. Compliance with this directive is crucial for telemetric systems to ensure that they do not interfere with other electronic devices and can operate reliably without being affected by electromagnetic interference.

Key aspects include:

• Emission limits: Ensuring the device does not emit excessive electromagnetic interference.
• Immunity requirements: Ensuring the device can operate correctly in the presence of electromagnetic disturbances.
• Testing and documentation: Conducting appropriate EMC testing and maintaining detailed documentation.

2.2.2.      Low Voltage Directive (LVD)

The Low Voltage Directive (2014/35/EU) applies to electrical equipment operating with a voltage between 50 and 1000 V for alternating current and between 75 and 1500 V for direct current. This directive ensures that the equipment is safe to use and does not pose any electrical hazards to users or the environment.

Key aspects include:

• Electrical safety: Ensuring that the design and construction of the device prevent electric shock and other hazards.
• Mechanical safety: Ensuring that the device is mechanically safe, including protection against moving parts and structural integrity.
• Thermal safety: Ensuring the device does not overheat and cause burns or fires.
• Compliance testing: Conducting relevant tests to verify compliance with safety requirements.

2.2.3.      Radio Equipment Directive (RED)

The Radio Equipment Directive (2014/53/EU) covers radio equipment and ensures that it effectively uses the radio spectrum to avoid harmful interference. It also ensures that radio equipment is safe and does not endanger health.

Key aspects include:

• Efficient use of spectrum: Ensuring the device uses the radio spectrum effectively and avoids interference.
• Safety and health: Ensuring the device does not pose risks to health and safety.
• Interoperability: Ensuring the device can operate with other devices and systems.
• Testing and certification: Conducting tests to demonstrate compliance with the directive's requirements.

2.3.  Role of IEC Standards in CE Compliance

IEC standards play a critical role in CE compliance by providing detailed technical guidelines and performance criteria. These standards help manufacturers ensure their telemetric systems meet the specific requirements of relevant EU directives. By adhering to IEC standards, manufacturers can streamline their compliance processes, reduce the risk of non-conformity, and facilitate the CE marking process.

Key benefits include:

• Harmonization: Ensuring products meet harmonized standards recognized across the EEA.
• Testing and Validation: Providing clear guidelines for testing and validation procedures.
• Documentation: Offering structured frameworks for maintaining compliance documentation.
• Market Access: Facilitating easier access to the European market by meeting recognized standards.

By understanding and adhering to the regulatory framework and relevant directives, manufacturers of telemetric applications can ensure their products achieve CE marking, demonstrating compliance with essential health, safety, and environmental protection requirements.

3   Compliance Process

Achieving CE compliance for telemetric applications involves a structured process that ensures all regulatory requirements are met. This section outlines the essential steps manufacturers must follow to achieve CE marking.

3.1.  Identify Applicable Directives and Standards

The first step in the compliance process is to determine which EU directives and harmonized standards apply to the telemetric device. Key directives for telemetric applications typically include the Radio Equipment Directive (RED), Electromagnetic Compatibility (EMC) Directive, and Low Voltage Directive (LVD). Additionally, relevant harmonized standards should be identified and referenced.

3.2.  Perform Risk Assessment and Analysis

Conducting a thorough risk assessment is crucial to identify potential hazards associated with the telemetric device. This involves:

• Analyzing the intended use and misuse of the device.
• Identifying potential safety and health risks.
• Evaluating the likelihood and severity of these risks.
• Implementing design and manufacturing controls to mitigate identified risks.

3.3.  Conduct Testing and Evaluation

Testing is a critical component of the compliance process. The device must undergo various tests to ensure it meets the necessary technical and safety requirements:

• EMC Testing: Ensures the device does not emit or is not susceptible to electromagnetic interference.
• Radio Performance Testing: Verifies that the device operates effectively within its designated frequency bands and does not cause harmful interference.
• Safety Testing: Assesses the device's electrical safety, including protection against electric shock, fire hazards, and other safety risks.

Testing should be conducted in accredited laboratories to ensure accuracy and reliability.

3.4.  Compile Technical Documentation

Manufacturers must compile comprehensive technical documentation, known as the Technical File, which demonstrates compliance with all relevant directives. The Technical File should include:

• Detailed product description and specifications.
• Design and manufacturing drawings.
• Test reports and certificates from accredited laboratories.
• Risk assessments and mitigation measures.
• User manuals and installation instructions.

3.5.  Affix the CE Mark and Draft the EU Declaration of Conformity

Once the device meets all necessary requirements, the manufacturer can affix the CE mark to the product. This mark must be placed visibly, legibly, and indelibly on the product, its packaging, or accompanying documentation.

Simultaneously, the manufacturer must draft and sign the EU Declaration of Conformity (DoC). The DoC is a formal statement declaring that the product complies with all relevant directives and standards. It should include:

• Product identification details.
• List of applicable directives and standards.
• Manufacturer’s name and address.
• Signature of the authorized representative.

3.6.  Summary of the Compliance Process

• Identify Applicable Directives and Standards: Determine the relevant EU directives and harmonized standards for the telemetric device.
• Perform Risk Assessment and Analysis: Identify and mitigate potential risks associated with the device.
• Conduct Testing and Evaluation: Ensure the device meets EMC, radio performance, and safety requirements through rigorous testing.
• Compile Technical Documentation: Prepare a comprehensive Technical File demonstrating compliance.
• Affix the CE Mark and Draft the EU Declaration of Conformity: Mark the product with the CE mark and prepare the DoC.

By following these steps, manufacturers can ensure their telemetric applications comply with CE marking requirements, facilitating smooth market entry into the European Economic Area.

4     Testing and Certification

Testing and certification are crucial steps in the CE compliance process, ensuring that telemetric devices meet all relevant technical and safety requirements. This section provides an overview of the necessary tests, focusing on EMC, radio performance, and safety testing.

4.1.  Overview of Necessary Tests for CE Compliance

To achieve CE marking, telemetric devices must undergo rigorous testing to demonstrate compliance with applicable directives. The main categories of tests include:

• Electromagnetic Compatibility (EMC) Testing
• Radio Performance Testing
• Safety Testing

4.2.  Electromagnetic Compatibility (EMC) Testing

EMC testing ensures that the telemetric device does not emit excessive electromagnetic interference and is immune to electromagnetic disturbances.

4.2.1.      Emission Tests

• Radiated Emission: Measures the electromagnetic emissions from the device in the frequency range of 30 MHz to 1 GHz (or higher, depending on the application). Standards such as CISPR 32 or EN 55032 are commonly used.
• Conducted Emission: Measures the electromagnetic emissions conducted along power lines and Signal Lines in the frequency range of 150 kHz to 30 MHz. Standards like CISPR 22 or EN 55022 are applicable.
• Harmonic Emission: The harmonic emission test assesses the device's emissions of harmonics, which are multiples of the fundamental frequency. These emissions can cause interference in power supply networks. Standards such as IEC/EN 61000-3-2 (for equipment ≤ 16A per phase) or IEC/EN 61000-3-12 (for equipment > 16A per phase) define the test methods and limits for harmonic emission testing.
• Flicker Emission: The flicker emission test evaluates the device's emissions of voltage fluctuations, which can cause flickering in lighting systems and affect the quality of electrical supply. The IEC/EN 61000-3-3 standard specifies the test methods and limits for flicker emission testing.

4.2.2.      Immunity Tests

• Electrostatic Discharge (ESD): Assesses the device's immunity to electrostatic discharges. The standard IEC/EN 61000-4-2 is typically used.
• Radiated Immunity: Evaluates the device's immunity to radiated electromagnetic fields in the frequency range of 80 MHz to 1 GHz (or higher). The standard IEC/EN 61000-4-3 applies.
• Conducted Immunity: Tests the device's immunity to conducted disturbances in the frequency range of 150 kHz to 80 MHz. The standard IEC/EN 61000-4-6 is used.
• Conducted Susceptibility: The conducted susceptibility test evaluates the device's susceptibility to conducted disturbances induced through power and signal lines. The IEC/EN 61000-4-6 standard provides guidelines for conducted susceptibility testing.
• Power Frequency Magnetic Field: The power frequency magnetic field immunity test evaluates the device's immunity to magnetic fields at power frequencies (50 Hz or 60 Hz). The IEC/EN 61000-4-8 standard specifies the test methods and requirements for power frequency magnetic field immunity testing.
• Surge Immunity: Assesses the device's ability to withstand high-voltage surges. The standard IEC/EN 61000-4-5 applies.
• Electrical Fast Transient/Burst (EFT/B): Tests the device's immunity to fast transients and bursts. The standard IEC/EN 61000-4-4 is used.
• Voltage Dips and Interruptions: The voltage dip and interruption immunity test assesses the device's ability to withstand short-term voltage dips and interruptions in the electrical supply. The IEC/EN 61000-4-11 standard defines the test procedures and requirements for voltage dip and interruption immunity testing.
• Voltage Variation: The voltage variation immunity test assesses the device's immunity to variations in the electrical supply voltage. The IEC/EN 61000-4-11 standard defines the test procedures and requirements for voltage variation immunity testing.

4.3.  Radio Performance Testing

Radio performance testing ensures that the telemetric device uses the radio spectrum efficiently and does not cause harmful interference.

4.3.1.      Essential Radio Tests

• Frequency Stability: Measures the stability of the device's operating frequency over varying environmental conditions (temperature, voltage). Standards like ETSI EN 300 220 or ETSI EN 300 328 apply.
• Output Power: Verifies that the device's output power is within the specified limits to prevent interference. Standards such as ETSI EN 300 328 or ETSI EN 301 893 are used.
• Receiver Sensitivity and Selectivity: Evaluates the device's ability to detect weak signals and reject unwanted signals, ensuring reliable communication. Standards like ETSI EN 300 328 or ETSI EN 301 893 apply.
• Adjacent Channel Power: Measures the power emitted in adjacent channels to ensure minimal interference with neighbouring frequencies. Standards like ETSI EN 300 328 or ETSI EN 301 489-1 are applicable.
• Occupied Bandwidth: Ensures that the device's signal occupies the designated bandwidth and does not interfere with adjacent channels. Standards such as ETSI EN 300 328 or ETSI EN 301 893 are used.

4.4.  Safety Testing

Safety testing ensures that the telemetric device is safe for users and does not pose any electrical, mechanical, or thermal hazards.

4.4.1.      Electrical Safety Tests

• Dielectric Voltage Withstand Test (Hipot Test): Verifies the insulation strength by applying high voltage between the electrical circuits and chassis. Standards like IEC/EN 60950-1 or IEC/EN 62368-1 are used.
• Leakage Current Test: Measures the leakage current flowing through the device's insulation to ensure it is within safe limits. Standards such as IEC/EN 60950-1 or IEC/EN 62368-1 apply.
• Ground Continuity Test: Ensures the integrity of the ground connection in the device to protect against electric shock. Standards like IEC/EN 60950-1 or IEC/EN 62368-1 are used.
• Insulation Resistance Test: The insulation resistance test measures the insulation resistance between conductive parts and accessible surfaces of the device. It ensures that the insulation is intact and can withstand electrical stresses. The IEC/EN 60950-1 or IEC/EN 62368-1 standards specify the test methods and requirements for insulation resistance testing.
• Ground Continuity Test: The ground continuity test verifies the integrity of the ground connection in the device. It ensures that the device has a reliable path to ground, which is essential for electrical safety. The IEC/EN 60950-1 or IEC/EN 62368-1 standards define the test methods and requirements for ground continuity testing.
• Earth Bond Resistance Test: The earth bond resistance test evaluates the resistance of the protective earth connection in the device. It ensures that the protective earth connection is robust and can effectively carry fault currents to ground. The IEC/EN 60950-1 or IEC/EN 62368-1 standards define the test methods and requirements for earth bond resistance testing.
• Leakage Current Test: The leakage current test measures the current that flows from conductive parts or components within the device to the enclosure or chassis. It ensures that leakage currents do not exceed safe limits. The IEC/EN 60950-1 or IEC/EN 62368-1 standards specify the test methods and limits for leakage current (enclosure leakage) testing.
• Touch Current and Protective Conductor Current Test: The touch current and protective conductor current test assesses the leakage current that may flow through accessible parts of the device or the protective conductor. It ensures that leakage currents are within safe limits to prevent electric shock. The IEC/EN 60950-1 or IEC/EN 62368-1 standards specify the test methods and limits for touch current and protective conductor current testing.

4.4.2.      Mechanical Safety Tests

• Drop Test: Assesses the device's ability to withstand drops and impacts during normal handling and use. Standards like IEC 60068-2-32 are commonly used.
• Vibration Test: Evaluate the device's resistance to vibrations that may occur during transportation or operation. Standards such as IEC 60068-2-6 apply.

4.4.3.      Thermal Safety Tests

• Temperature Rise Test: Measures the temperature rise in the device's components to ensure it operates within safe limits. Standards like IEC/EN 60950-1 or IEC/EN 62368-1 are used.
• Overload Test: Assesses the device's ability to handle electrical overloads without failure. Standards such as IEC/EN 60950-1 or IEC/EN 62368-1 apply.

4.5.  Choosing a Notified Body

For certain categories of telemetric devices, particularly those with complex technology or higher risk, involving a notified body is required or recommended. A notified body is an independent organization designated by an EU country to assess the conformity of certain products before being placed on the market. They can assist with:

• Reviewing the Technical File.
• Conducting additional testing.
• Issuing certificates of conformity.

4.6.  Certification Process and Documentation

After successful testing, the following documentation must be prepared and maintained:

• Technical File: Includes all design, manufacturing, and testing documentation.
• EU Declaration of Conformity (DoC): A formal statement that the product complies with all relevant directives.
• CE Marking: Affixed to the product and its packaging.

By following these testing and certification steps, manufacturers can ensure their telemetric devices meet all CE marking requirements, guaranteeing safety, reliability, and market acceptance within the European Economic Area.

5      Documentation and Record Keeping

5.1.  Technical File

The Technical File is a comprehensive document that contains all the information and evidence demonstrating the compliance of the telemetric device with relevant EU directives and standards. It serves as a reference for regulatory authorities and must be kept up to date throughout the device's lifecycle.

5.1.1.      Contents of the Technical File:

• Product Description: Detailed description of the telemetric device, including its intended use, features, and functionality.
• Design and Manufacturing Drawings: Schematics, layouts, and diagrams that illustrate the device's design and components.
• Risk Assessment: Documentation of the risk assessment process, including identified hazards, risk mitigation measures, and safety considerations.
• Test Reports and Certificates: Results of all tests conducted during EMC, radio performance, and safety testing. Test reports should be from accredited laboratories.
• Compliance Documentation: Copies of relevant EU directives, harmonized standards, and technical specifications that the device complies with.
• User Manuals and Instructions: Comprehensive user manuals, installation guides, and operating instructions for the device.
• Declaration of Conformity: Signed EU Declaration of Conformity (DoC) declaring the device's compliance with all applicable directives and standards.
• Quality Control Records: Documentation of quality control processes, inspections, and checks conducted during manufacturing.
• Component and Supplier Information: Details of components used in the device, including suppliers, specifications, and conformity assessments.
• Service and Maintenance Records: Information on servicing, maintenance procedures, and recommended intervals for inspections and updates.
• Revision History: Record of any changes or updates made to the Technical File, including revision dates and reasons for modifications.
• Authorized Representative Details: Contact information of the authorized representative responsible for regulatory compliance within the EU.

5.2.  EU Declaration of Conformity (DoC)

The EU Declaration of Conformity is a formal document signed by the manufacturer or their authorized representative declaring that the telemetric device complies with all relevant EU directives and standards. It must accompany the product and be available upon request by regulatory authorities.

5.2.1.      Contents of the EU Declaration of Conformity:

• Product Identification: Details identifying the telemetric device, including model number, serial number, and batch information.
• List of Directives and Standards: Enumerates the EU directives and harmonized standards that the device complies with.
• Manufacturer Information: Name, address, and contact details of the manufacturer or their authorized representative.
• Authorized Representative Information: Contact information of the authorized representative if applicable.
• Compliance Statement: A statement affirming that the device meets all essential requirements of the relevant directives and standards.
• Signature and Date: Signed by an authorized person representing the manufacturer or their authorized representative, with the date of issuance.

5.3.  Record Keeping

Manufacturers of telemetric devices must maintain accurate and up-to-date records related to the design, production, testing, and compliance of the device. Records should be organized, accessible, and retained for a specified period to demonstrate ongoing compliance and facilitate traceability.

5.3.1.      Key Record-Keeping Practices:

• Test Records: Detailed records of all tests conducted, including test protocols, results, equipment calibration records, and test reports from accredited laboratories.
• Quality Control Records: Documentation of quality control procedures, inspections, audits, corrective actions, and product recalls.
• Supplier and Component Records: Records of suppliers, component specifications, conformity assessments, and supply chain traceability.
• Technical Documentation: Copies of technical specifications, design documents, risk assessments, user manuals, and installation instructions.
• Change Management Records: Records of any changes or modifications made to the device design, manufacturing processes, or materials, including revision history and reasons for changes.
• Complaints and Feedback: Records of customer complaints, feedback, and inquiries related to the device's performance, safety, or quality.
• Service and Maintenance Records: Documentation of service history, maintenance procedures, updates, and revisions.
• EU Declaration of Conformity (DoC): Copies of signed EU Declaration of Conformity documents for each device model.

5.4.  Retention Period

The retention period for documentation and records related to telemetric devices may vary based on regulatory requirements and the device's lifecycle. Generally, records should be retained for a minimum period of 10 years after the last unit of the device is placed on the market or made available.

5.4.1.      Benefits of Effective Documentation and Record Keeping:

• Demonstrates compliance with regulatory requirements.
• Facilitates traceability and recalls if necessary.
• Supports quality assurance and continuous improvement processes.
• Provides evidence of product safety, performance, and reliability.
• Enables efficient response to regulatory inquiries, audits, and inspections.

By implementing robust documentation and record-keeping practices, manufacturers can ensure regulatory compliance, product quality, and customer satisfaction throughout the lifecycle of telemetric devices.

6      Conclusion

Ensuring compliance with CE requirements for telemetric applications is a multifaceted process that involves a deep understanding of regulatory frameworks, rigorous technical testing, meticulous documentation, and effective risk management. As telemetric devices become increasingly integrated into various sectors, the importance of meeting these stringent regulatory standards cannot be overstated.

The challenges associated with CE compliance, including complex regulations, extensive testing, and maintaining comprehensive documentation, can be daunting. However, by leveraging expert guidance, utilizing accredited testing facilities, implementing robust documentation systems, and adopting a proactive approach to risk management, manufacturers can navigate these challenges successfully.

Key to this process is a thorough understanding of the regulatory landscape, continuous monitoring and updating of compliance practices, and a commitment to maintaining high standards of quality and safety throughout the product lifecycle. Engaging with notified bodies, conducting regular audits, and fostering strong supply chain relationships further enhance the compliance process, ensuring that telemetric devices not only meet current requirements but are also prepared for future regulatory changes.

Ultimately, achieving CE compliance not only facilitates access to the European market but also enhances the overall reliability, safety, and marketability of telemetric devices. By prioritizing compliance, manufacturers can build trust with customers, reduce the risk of market withdrawals, and ensure their products contribute positively to the growing field of telemetric applications.

Through diligent adherence to regulatory standards and proactive management of compliance processes, manufacturers can position themselves for success in the competitive landscape of telemetric technology, ensuring their products are safe, effective, and ready for the global market.

References

• European Commission. "CE Marking." Available at: https://ec.europa.eu/growth/single-market/ce-marking_en
• European Telecommunications Standards Institute (ETSI). "EN 301 489-1: Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 1: Common technical requirements." Available at: https://www.etsi.org/deliver/etsi_en/301400_301499/30148901/02.02.02_60/en_30148901v020202p.pdf
• European Committee for Electrotechnical Standardization (CENELEC). "EN 62368-1: Audio/video, information and communication technology equipment - Part 1: Safety requirements." Available at: https://standards.cen.eu/dyn/www/f?p=CENWEB:110:::NO:21:P21_FSD_ID:6360589&cs=11CF1B55A7DE7FAD5A083FD0E69E8CD12
• International Electrotechnical Commission (IEC). "IEC 61000-4-2: Electromagnetic compatibility (EMC) - Part 4-2: Testing and measurement techniques - Electrostatic discharge immunity test." Available at: https://webstore.iec.ch/publication/4194
• International Electrotechnical Commission (IEC). "IEC 61000-4-3: Electromagnetic compatibility (EMC) - Part 4-3: Testing and measurement techniques - Radiated, radio-frequency, electromagnetic field immunity test." Available at: https://webstore.iec.ch/publication/4195
• International Electrotechnical Commission (IEC). "IEC 61000-4-4: Electromagnetic compatibility (EMC) - Part 4-4: Testing and measurement techniques - Electrical fast transient/burst immunity test." Available at: https://webstore.iec.ch/publication/4196
• International Electrotechnical Commission (IEC). "IEC 61000-4-5: Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement techniques - Surge immunity test." Available at: https://webstore.iec.ch/publication/4197
• International Electrotechnical Commission (IEC). "IEC 61000-4-6: Electromagnetic compatibility (EMC) - Part 4-6: Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields." Available at: https://webstore.iec.ch/publication/4198
• International Electrotechnical Commission (IEC). "IEC 61000-4-8: Electromagnetic compatibility (EMC) - Part 4-8: Testing and measurement techniques - Power frequency magnetic field immunity test." Available at: https://webstore.iec.ch/publication/4199
• International Electrotechnical Commission (IEC). "IEC 61000-4-11: Electromagnetic compatibility (EMC) - Part 4-11: Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests." Available at: https://webstore.iec.ch/publication/4200