Overview
ISO 11452-2:2019 specifies an absorber-lined shielded enclosure (ALSE) method for electromagnetic immunity testing of road-vehicle electronic components. It defines how to expose a device under test (DUT) - with its wiring harness and peripheral devices - to narrowband radiated electromagnetic energy (continuous fields) generated inside an ALSE. Applicable to passenger cars and commercial vehicles regardless of propulsion (ICE, diesel, electric), the standard covers laboratory component-level testing that simulates off-vehicle radiation sources.
Keywords: ISO 11452-2, absorber-lined shielded enclosure, ALSE, electromagnetic immunity testing, road vehicles, DUT, narrowband radiated electromagnetic energy.
Key topics and technical requirements
- Scope and frequency range: Test method applicable for 80 MHz to 18 GHz and limited to continuous narrowband fields; general test conditions are defined in ISO 11452-1.
- ALSE design objective: Absorbing material on walls/ceiling to reduce reflections by at least 10 dB in the test area; floor may optionally use ferrite tiles (≤25 mm).
- Ground plane: Minimum 0.5 mm thick copper/brass/galvanized steel; minimum width 1 000 mm and length 2 000 mm (with rules to expand based on DUT footprint); bench height 900 ± 100 mm; DC bonding resistance ≤ 2.5 mΩ; ground strap spacing ≤ 300 mm; strap length/width ratio ≤ 7:1.
- Test equipment: RF generator (with modulation), high-power amplifiers, field-generating antennas, field probes (electrically small, isotropic, 3-axis) with fibre-optic links, power meters/dual directional couplers, and appropriate artificial networks (AN, HV-AN, AMN, AAN) for power leads.
- DUT stimulation & monitoring: Use nonconductive actuators (plastic/pneumatic) to operate DUT; monitoring connections should use fibre optics or high-resistance leads to avoid EM interactions.
- Test procedure elements: Set-up and calibration (including substitution method and field calibration), execution of DUT test, and test reporting are specified (see Clause 9).
Applications and users
- Who uses it: Automotive EMC engineers, component suppliers, test laboratories, R&D and quality teams involved in vehicle electronics and subsystem validation.
- Practical uses:
- Component immunity verification during development and production validation.
- Replacing or supplementing full-vehicle open-field tests when prototype secrecy, cost, or availability restricts vehicle-level testing.
- Evaluating harness routing, artificial networks, and grounding strategies under controlled narrowband radiated fields.
Related standards
- ISO 11452-1:2015 - General principles and terminology for narrowband radiated immunity component tests (normative reference).
- IEEE STD 1128-1998 - referenced for absorber material evaluation.
ISO 11452-2 is essential when implementing laboratory-based electromagnetic compatibility (EMC) programs for modern vehicle electronic components and helps ensure consistent, repeatable narrowband radiated immunity testing in ALSE facilities.