EMI shield Effectiveness Testing

The modern world has a proliferation of small and large electronic devices and systems that are all susceptible to electromagnetic interference. EMI should be a significant concern for any electronics manufacturer because electronics emit EMI, and equipment will be negatively affected when exposed to external EMI sources. When this type of energy interacts unintentionally with other devices, it can cause malfunctions. EMI is typically within a range of 1 kilohertz – 10 gigahertz. This range is referred to as an RFI band (including audio and radio frequencies). The most common source of interferences comes from motors, televisions, and radar transmitters. EMI shielding is used to prevent EMI leakage and to prevent unwanted EMI from entering devices.

EMI Shielding

It is crucial that manufacturers test the effectiveness of their shields. Several standard tests can be employed to find out the exact results.

The most commonly used method is the open field test, which is designed to simulate typical use conditions (as closely as possible). Antennae are used, at varying distances from the device, in areas that have no metallic materials beside the testing equipment. This test must be done in an open site that allows for free space measurements of conductive emissions and radiated field strength. A noise level meter is used to detect the amount of EMI produced. This testing method is often used for finished electronic products.

Other testing methods include:

  1. Coaxial transmission line test
  2. Shielded box test
  3. Shielded room test

EMI shielding

For more information on EMI shielding tests, you should give our team a call. We handle all EMI gasket and shielding needs.

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