What an EMC test plan must contain

Most time lost on test day comes from a thin plan. Filling in the items below puts the test lab and the design team on the same page.

Sample and configuration

• Sample name, model, versions (hardware and firmware) and serial number.
• Rated supply (voltage, frequency) and test supply conditions.
• Every port to be connected, with cable type, length, shielding and the equipment on the other end (auxiliary equipment).
• Sample placement (tabletop or floor-standing), cable layout and photos or drawings.

Operating modes

• The worst-case mode for emissions (maximum load, highest clock, all ports active) and why it was chosen.
• Functions to monitor during immunity tests and how to verify them (display, communication log, LED).
• How the software state is kept automatically during the test.

Standards and pass criteria

• Standard numbers and editions, product class (Class A/B, etc.) and the list of tests.
• Immunity test levels and the product-specific definition of the criteria (A/B/C, etc.).
• Limits, distance and detector combination.
• Agreement on how uncertainty is handled (direct comparison or guard band).

Records and schedule

• List of equipment used and calibration validity.
• How environmental conditions (temperature, humidity) are recorded.
• Retest scope and schedule after countermeasures if a test fails.

Field notes

• Every cable must be listed in the test procedure, yet missing cables are often discovered while setting up in the chamber. Verify the configuration thoroughly with the client before the test.
• Also confirm whether each cable is shielded and how the product is mounted (grounded, on a jig, etc.) and write it in the plan.