EMC Testing Preparation Checklist
Proper preparation is one of the most effective ways to ensure a successful compliance test session. Every hour of lab time spent resolving preventable preparation issues costs money and delays your certification. Use this checklist to confirm your product, documentation, support equipment, and team are fully ready before your scheduled test date.
EUT PreparationDocumentationImmunity CriteriaDay-of Logistics
Why Preparation Matters
The most common avoidable test session problems — each of which extends chamber time and increases cost:
⚠ AvoidTop Preparation Failures
- Firmware not at release version — subsequent updates require retesting
- Missing cables or peripherals — wrong cables mean untestable configurations or rescheduling
- Undefined performance criteria — immunity tests cannot be assessed without pre-agreed pass/fail criteria
- EUT not fully functional — worst-case emissions modes cannot be measured
- Insufficient spare units — immunity testing can damage the EUT; one spare minimum
- No decision authority reachable — unexpected configuration issues arise in every test session
✅ The payoff: A fully prepared test session at Compatible Electronics runs smoothly, on schedule, and on budget — with your engineer present to observe results and respond immediately to any configuration questions.
✓ Product (EUT) Preparation
- Final or near-final production version — engineering prototypes with hand-wired modifications are not representative
- All covers, panels, and enclosures installed and properly secured — test in shipping configuration
- Product fully functional in all intended modes — verify the day before, not the morning of the test
- Firmware/software at the release version intended for market submission — document the version number
- Properly labeled with model number, input ratings, and all required markings
- Spare units available — bring at least one additional unit; ESD and surge tests can cause damage
- All operating modes documented — identify which mode produces worst-case emissions (typically: all interfaces active, maximum clock frequency, maximum data throughput)
✓ Documentation to Provide
- User manual or draft operating instructions — describes intended use and interface configurations
- Technical specifications — rated input voltage, power consumption, output specifications
- Block diagram — shows all functional blocks, interface connections, and power supply architecture
- List of all I/O ports and their functions — every port must be identified for immunity injection (AC mains, DC, USB, Ethernet, RS-232, RS-485, HDMI, antenna, etc.)
- Description of all operating modes — specify worst-case emissions mode and representative immunity monitoring mode
- Applicable standards list — confirm which standards apply and which market(s) the test supports
- Previous test reports if available — for re-tests or updates, provide prior reports so the test engineer understands the history
✓ Support Equipment & Cables
- All power cords and AC adapters — every variant (US, EU, UK) in production-intent form
- All signal cables — every type and length that ships with or connects to the product
- Representative load equipment or simulators — for powered outputs, bring the representative load or calibrated simulator
- Peripherals needed for normal operation — keyboard, mouse, display, storage devices, etc.
- Test software or applications — installed and verified functional before arriving at the lab
- Monitoring equipment if needed — oscilloscope, data logger, or custom software your team uses to assess product function
✓ Emissions Test Configuration
Emissions PrepWorst-Case Configuration
- Identify the worst-case emissions operating mode before arriving — all interfaces simultaneously active, maximum clock frequency, maximum data throughput
- For switchable modes (Wi-Fi on/off, Bluetooth on/off) — plan which combinations require testing
- For Class A vs. Class B — confirm intended use environment before the test; changing class mid-session adds time
- For conducted emissions — identify which ports have LISNs (AC mains, DC input) and source impedance at customer sites
- For products with multiple cable lengths — longest cables typically produce worst-case radiated emissions
Immunity PrepPerformance Criteria — Define Before Arriving
- For each immunity test, document what constitutes Criterion A (normal performance maintained), Criterion B (temporary degradation allowed), and Criterion C (operator intervention permitted)
- Identify the representative function to monitor during each immunity test — which output signal, display state, or communication link will be observed
- For CE marking: performance criteria must be defined by the manufacturer and documented in the technical file — not decided at the test lab
- For medical devices (IEC 60601-1-2): essential performance definition must be agreed and documented before testing begins
✓ Day-of Logistics
- Confirm test date, time, and location (Lake Forest/Silverado, Brea, or Newbury Park) with Compatible Electronics at least 48 hours in advance
- Ship or transport the product safely — adequate padding, ESD-protective packaging, fragile labels if needed
- Bring contact information for your engineering team — someone who can answer technical questions must be reachable by phone during the test session
- Know your deadline — communicate hard Declaration of Conformity or regulatory submission dates when scheduling so the lab can plan accordingly
- Bring decision authority — if an unexpected configuration question arises, someone with technical decision authority must be present or immediately reachable
- Bring this checklist and your test plan — the test engineer will use both to confirm readiness before starting
Ready to Schedule Your EMC Testing?
Contact Compatible Electronics to schedule your test session — three Southern California locations, same-day or next-day pre-compliance available.
Brea: 714‑579‑0500 · Newbury Park: 805‑480‑4044
www.celectronics.com
