IEEE-299 is the standard procedure for measuring the effectiveness of electromagnetic shielding enclosures. The shielding effectiveness (SE) testing procedure covers more common frequencies from 9 kHz to 18 GHz. The most common enclosure Gaven tests with this procedure is a hospital or outpatient MRI room. Although, this standard can be used for testing any commercial/government facility, such as a SCIF or metrology facility.
Testing to IEEE 299 requires placing transmitting and receiving antennas on each side of the enclosure wall. As a RF signal generator output connects to a transmit antenna, the exterior enclosure surface is illuminated with RF waves. A scanning receiving antenna inside the enclosure measures the maximum leakage signal at that location. This process is essentially repeated around the outer limits of the enclosure for each test frequency.