Introduction: Why EMC Sample Preparation Matters
Before your device enters the test chamber, proper sample preparation is essential. At MiCOM Labs, accurate Electromagnetic Compatibility (EMC) testing depends on representative setups that mimic real-world operation. Missing accessories, incomplete configurations, or unclear instructions can delay testing and certification timelines.
This guide explains how to prepare EMC samples correctly for emission and immunity testing, including setup examples and performance criteria.
1. EMC Emission Testing Requirements
During emission testing, the goal is to measure the electromagnetic energy emitted by your product under normal operating conditions. To obtain accurate and repeatable results, the test configuration must reflect real-life usage.
| Requirement | Description | Example / Notes |
| Accessories and Support Equipment | Provide all accessories and external devices required for operation. | Include chargers, cables, laptops, or communication modules. |
| Populated I/O Ports | Every input/output port should have representative loads. | Use dummy loads or functional peripherals. |
| Continuous Operation | The sample must run continuously in its intended mode. | Maintain active communication, charging, or data transfer. |
| Multiple Modes | If the device supports multiple modes, each must be testable. | Wi-Fi active mode, charging mode, motor operation, etc. |
| Control Interface | Provide a method to operate or monitor the device remotely. | Serial, USB, or LAN interfaces available for chamber use. |
| Cellular Access | Ensure SIM card access is possible. | Required for cellular tests using MiCOM’s base station emulators; include in immunity setup as well. |
| Frequency Stability | Provide environmental operating ranges for voltage and temperature. | Helps verify compliance with FCC §2.1055 and similar regulations. |
| Sample Labeling | Each sample should be uniquely identified with model number, serial number, firmware version, and configuration ID. | Facilitates traceability and regulatory submissions. |
| Photographic Documentation (Optional) | Include photos or diagrams of the device and setup if available. | Helps ensure test consistency and assists with regulatory submissions. |
| Cable Routing | Use representative cable lengths and layout per CISPR 32 / EN 55032 guidelines. | Ensures repeatable and accurate emission measurements. |
| Power Configuration | Include AC/DC adapters, battery simulators, or instructions for continuous external powering. | Maintains consistent emission testing conditions. |
| Grounding / Shielding | Provide grounding or shielding instructions where applicable. | Ensures reproducible test results. |
| Software Stability | Disable automatic updates, sleep modes, or power-saving functions that could interrupt testing. | Maintains device stability during extended testing. |
Tip: MiCOM’s anechoic chambers allow remote operation via serial, USB, and LAN interfaces. Please verify remote connectivity before shipment of samples.
2. EMC Immunity Testing Requirements
Immunity testing evaluates how your device performs when exposed to electromagnetic disturbances such as RF fields, electrostatic discharge (ESD), voltage surges, or power dips.
| Requirement | Description | Example / Notes |
| Performance Monitoring | Must be possible to monitor performance during tests. | Monitor throughput, bit error rate, or wireless link stability. |
| Multiple Modes | Each operational mode must be validated under stress. | Test each function individually – communication, charging, etc. |
| Companion Device | Required if the EUT communicates with another device. | E.g., paired receiver, base unit, or smartphone. |
| Remote Monitoring Access | Enable test engineer visibility during stress conditions. | USB, LAN, or serial connections preferred. |
| Detailed Instructions | Provide clear steps for mode initialization and recovery. | Include troubleshooting or reboot procedures. |
| Reference Standards | Configure samples to recover after exposure to IEC 61000-4-2 (ESD), 61000-4-3 (RF Immunity), 61000-4-4 (EFT/Burst), 61000-4-5 (Surge), 61000-4-11 (Voltage Dips and Interruptions). | Ensures compliance with international EMC standards. |
| Power Configuration | Include AC/DC adapters, battery simulators, or instructions for continuous external powering. | Helps maintain consistent immunity testing conditions. |
| Grounding / Shielding | Provide grounding or shielding instructions for cables and test setup. | Ensures reproducible test results. |
| Software Stability | Disable automatic updates, sleep modes, or power-saving features. | Maintains device stability during extended testing. |
| Equipment Identification | Label all samples with model number, serial number, firmware version, and configuration ID. | Supports regulatory reporting. |
| Photographic Documentation (Optional) | Include setup diagrams or photos of the EUT and test configuration. | Supports traceability and repeatability. |
| Power Interface Separation | Separate EUT power from auxiliary devices to prevent unintended coupling. | Reduces measurement errors during transient immunity tests. |
MiCOM Labs can provide cellular base station emulators to maintain and monitor live network connections during testing.
3. Performance Criteria for Immunity Testing
During immunity testing, devices are evaluated based on defined performance criteria (A, B, C) and additional criteria for radio equipment.
| Criterion | Description | Expected Behavior |
| A | Must operate as intended without degradation. | No performance loss or functional change allowed. |
| B | Temporary degradation during the test allowed, but must recover automatically. | Device resumes normal function post-test. |
| C | Temporary loss of function allowed if recoverable via normal controls. | Reboot or restart permitted; data must be retained. |
| Continuous Phenomena | For RF field immunity tests. | Maintain connection, prevent unintended transmissions or mode changes. |
| Transient Phenomena | For ESD, surge, EFT, or voltage dip tests. | No data loss; recover function post-disturbance. |
4. Common Pitfalls to Avoid
- Sending incomplete accessory kits or missing cables
- Not providing clear operating instructions for multiple modes
- Forgetting to populate I/O ports with representative loads
- Lack of remote access setup for chamber operation
- Omitting power supply or battery simulator details
- Missing grounding or shielding guidance
- Using non-representative cable lengths or layouts
- Firmware or software left in automatic update mode
- Failing to label samples or provide photographic documentation
Preparing these details in advance ensures testing starts on schedule and reduces the likelihood of re-tests.
5. Partner with MiCOM Labs
MiCOM Labs combines technical expertise and advanced testing capabilities to ensure your product meets worldwide EMC regulatory requirements with confidence.
Key Benefits:
- Guidance on emission and immunity test setup per FCC, ISED, RED, MIC Japan, and UKCA standards
- Support for power configuration, grounding, cable layout, and transient immunity tests
- Assistance with sample labeling, firmware stability, and photographic documentation
- Remote verification to reduce delays and prevent setup errors
Need help preparing your EMC samples? Contact MiCOM Labs today: