Test purpose and protected receiver
Measure emissions from vehicle components and harnesses to protect onboard broadcast, mobile-communication, and navigation receivers.
ENGINEERING FLOW
01Understand→
02Control→
03Verify→
04Resolve→
05Document
TEST CENTER / CISPR 25 ALSE
CISPR 25 Component Radiated-Emission Test L5 Standard / primary source
This method page answers twelve engineering questions covering purpose, physics, scope, setup, calibration, operating state, criteria, common errors, and failure diagnosis.
METHOD CHECKLIST / 12 ENGINEERING QUESTIONS
Everything a professional test-method page must answer.
The method is cross-referenced by object, phenomenon, measurement technique, and standards framework. These questions define a reproducible engineering boundary.
Physical mechanism
The test observes the chain from an internal DUT source through harness common-mode current and spatial radiation to the receiving antenna.
Applicable objects and exclusions
Applies to vehicle components, modules, ECUs, and harnesses. Whole-vehicle external emissions are addressed by CISPR 12; low-frequency EV emissions by CISPR 36.
Standard, edition, status, and verification
CISPR 25:2021 is published and covers 150 kHz to 5.925 GHz. Last metadata check: 2026-07-11. Limits require a legally obtained standards text.
Equipment, harness, loads, auxiliaries, and environment
Use an absorber-lined shielded enclosure, artificial network, suitable antennas, representative loads, and a DUT positioned 50 mm above the ground reference plane.
Test setup and critical dimensions
Route the harness 50 mm above the reference plane for 1.5 m or the specified length. Position the antenna 1 m from the harness and scan required polarizations and heights.
Calibration, validation, and uncertainty
Maintain calibration of antenna factors, AN impedance, normalized site attenuation, and site VSWR. Key uncertainty sources include antenna factor, NSA, and harness repeatability.
Frequency, amplitude, detector, and dwell parameters
Apply the frequency-dependent limits and levels defined by CISPR 25. Receiver bandwidth, detector type, and dwell time follow the applicable clause.
DUT operating state, monitoring, and functional criteria
Test the worst-case emission state, monitor operation and functional outputs, and record enabled and disabled modes for source localization.
Common setup errors and laboratory differences
Frequent errors include incorrect harness geometry, poor AN bonding, out-of-tolerance chamber validation, non-worst-case operation, and inadequate supply-port isolation.
Failure diagnosis and corrective-action path
Normalize frequency, distinguish narrowband from broadband, localize the source, measure common-mode current, run one-variable A/B experiments, and regress the original setup.
Related case, primary source, and copyright
Related case: 150 MHz harness radiation. Source: CISPR 25:2021 metadata and public summaries only; the standards text is not reproduced.