Devices are tested for compliance with electromagnetic radiation standards through a series of rigorous tests performed in specialized testing facilities. These standards are put in place to ensure that electronic devices do not emit excessive electromagnetic radiation that could interfere with other devices or pose health risks to users. Here's an overview of the testing process:
Preparation: Before testing begins, the device manufacturer provides a detailed description of the device, its intended use, and the specific standards it needs to comply with. This information helps the testing facility set up appropriate test conditions.
Test Setup: The testing facility creates a controlled environment with calibrated equipment. The test setup typically includes an anechoic chamber, which is a shielded room designed to prevent outside interference and simulate free space conditions.
Radiated Emissions Test: The device under test is placed in the anechoic chamber, and its emissions are measured while it operates under various conditions (e.g., maximum power, different frequencies, different operational modes). The emissions are typically measured using spectrum analyzers and antennas.
Conducted Emissions Test: In addition to radiated emissions, devices are also tested for conducted emissions. This involves measuring electromagnetic interference that may be conducted through power cables and other connectors. The device is connected to specific test equipment to monitor the emissions on the cables.
Immunity Test: Apart from testing emissions, the device is also subjected to immunity tests to see how well it can withstand external electromagnetic interference. The device is exposed to controlled levels of electromagnetic radiation, and its performance is monitored to ensure it functions correctly without undue interference.
Specific Absorption Rate (SAR) Test: For wireless communication devices like smartphones, SAR testing is conducted to measure the amount of electromagnetic energy absorbed by the user's body during normal use. This is important to ensure that the device complies with safety guidelines regarding exposure to electromagnetic fields.
Reporting and Certification: Once all the tests are complete, the testing facility compiles a detailed test report that includes the test setup, measurements, and results. If the device meets the required standards, the manufacturer receives a certification of compliance. This certification is often a legal requirement for selling the device in various markets.
It's important to note that different regions or countries may have their own specific standards and regulations, such as FCC (Federal Communications Commission) in the United States, CE (Conformité Européene) in Europe, and others. Manufacturers must ensure their devices meet the appropriate standards for each market where they plan to sell the product.