Electromagnetic shielded chambers are designed to isolate indoor and outdoor electromagnetic environments, ensuring normal operation of electronic and electrical equipment. Particularly in metrology and testing of electronic components and appliances, these chambers (or anechoic chambers) simulate ideal electromagnetic conditions to enhance measurement accuracy. They are primarily used for conducted emission (CE) testing, discontinuous interference, disturbance power, tri-plate radiation, CDN radiation, and conducted immunity testing.
| Shielding Effectiveness | Metrics: Typically expressed in decibels (dB), e.g., 60-100 dB at low frequencies (14 kHz–1 MHz) and 80-120 dB at high frequencies (>1 MHz) Frequency Range: Covers DC to 40 GHz or higher to meet diverse testing needs. Magnetic Field Shielding: Specifically calibrated for low-frequency fields (e.g., 50 Hz power frequency), with attenuation up to 30 dB |
|---|---|
| Shielding Effectiveness | Structure and Materials Materials: Galvanized steel (cost-effective) Copper (superior high-frequency performance) Multi-layer composite metals Construction: Continuous welding or modular assembly with conductive gasket seals at joints Door Design: Knife-edge electromagnetic sealing door with pneumatic or mechanical compression Ventilation Waveguide: Honeycomb waveguide windows with apertures <1/20 of the highest frequency wavelength, ensuring ventilation while maintaining shielding Filters: Power/signal line filters with ≥60 dB insertion loss to suppress conducted interference |
| Environmental Control | Grounding Resistance: ≤1 Ω for optimal grounding Dimensions: Customizable; common sizes range from small/medium (3m×3m×2m) to large (20m×10m×8m) Temperature/Humidity: Integrated HVAC maintains 20–25°C and 30–60% RH |
| Emission Tests | Radiated Emissions (RE): Measures electromagnetic wave intensity per CISPR 16 Conducted Emissions (CE): Detects interference signals conducted via power/signal lines |
|---|---|
| Immunity Tests | Radiated Immunity (RS): Applies interference fields (e.g., 10 V/m via antennas) to verify device resilience Conducted Immunity (CS): Injects interference signals via coupling clamps to test cable immunity |
| Transient Pulse Tests | Field Attenuation Method: Compares indoor and outdoor field strength differences to validate shielding effectiveness Leakage Point Detection: Uses near-field probes or spectrum analyzers to locate shielding defects |
| Electronics Manufacturing | Pre-compliance EMC testing for consumer electronics (e.g., smartphones, PCs) to meet FCC/CE standards Automotive electronics (e.g., radar, BMS) radiated/immunity testing per ISO 11452 |
|---|---|
| Healthcare & Military | Electromagnetic safety evaluation for medical devices (MRI, pacemakers) per IEC 60601 High-shield testing for military equipment (radar, encrypted comms) per MIL-STD-461G |
| Research & Certification | Electromagnetic property studies of novel materials at universities/research institutes Compliance certification by third-party labs (e.g., Intertek, BV) |
| Telecom & Energy | Cross-interference testing for 5G base stations and satellite equipment Conducted interference analysis for PV inverters and smart meters |
