Semi-Anechoic Chambers for Electromagnetic Compatibility are primarily used to replace open test sites free of electromagnetic interference for measuring electromagnetic radiation emissions and electromagnetic radiation susceptibility. Since the testing environment in a semi-anechoic chamber needs to simulate the electromagnetic wave propagation conditions of an open test site (i.e., only direct and ground-reflected waves), the size of the chamber should be based on the structural requirements of the open test site, generally divided into standard 10m method, 5m method, and 3m method, etc. There are many types of semi-anechoic chambers, with significant differences in functionality, structural form, material selection, and installation methods. However, the choice of which scheme to use mainly depends on the type of test required by the user, the spatial dimensions of the object under test, and the test level. First, we need to clarify the test frequency range, whether it is for military standard testing or civilian standard testing, whether it is for internal pre-compatibility and diagnostic testing by the manufacturer, or for third-party certification testing; secondly, we need to clarify the maximum space the object under test may occupy, the main application standards of the laboratory, the financial situation, and the potential future expansion and upgrade needs, etc., to choose a suitable and feasible test site and instrument equipment configuration plan.
Semi-Anechoic Chambers can be categorized by size and functionality into 3m  Semi-Anechoic Chambers, 5m Semi-Anechoic Chambers, 10m Semi-Anechoic Chambers, CISPR25 Semi-Anechoic Chambers, and Military Standard Semi-Anechoic Chambers. To ensure the accuracy of electromagnetic compatibility tests, there are supporting shielding rooms, which are functionally divided into control rooms, power amplifier rooms, load rooms, and conducted rooms.