Basic structure forms of electromagnetic shielding rooms:

(1) Electromagnetic shielding rooms typically use cold-rolled steel plates or stainless steel plates as the main shielding material. This includes the six-sided shell, doors, windows, and other building elements, requiring a tight electromagnetic seal. All inlets and outlets are also subjected to corresponding shielding treatment to effectively block electromagnetic radiation from entering or exiting.

　  (2) Electromagnetic shielding rooms are categorized into three types: steel plate assembled, steel plate welded, and copper mesh. The assembled type is made by modules of 1.2mm thick steel plates, forming walls of 100mm thickness, with simpler production and installation processes, suitable for small areas or projects with lower shielding performance requirements. It can be disassembled and relocated, but the shielding effectiveness will significantly decrease after relocation. The welded steel plate type shielding room is constructed by welding 1.2mm cold-rolled steel plates to a skeletal frame, offering high shielding effectiveness and compatibility with various sizes, making it the primary form of electromagnetic shielding rooms. The copper mesh type is used for simpler projects with lower shielding performance requirements.

2. The primary function of an electromagnetic shielding room:

(1) Shield against external electromagnetic interference to ensure the normal operation of indoor electronic and electrical equipment. Particularly in the measurement and testing of electronic components and electrical equipment, use an electromagnetic shielding room (or a dark room) to simulate an ideal electromagnetic environment, thereby enhancing the accuracy of test results.

(2) Block the indoor electromagnetic radiation from spreading outward. Strong electromagnetic radiation sources should be shielded and isolated to prevent interference with the normal operation of other electronic and electrical equipment, and even to safeguard the health of staff members.

(3) Prevent information leakage from electronic communication equipment and ensure information security. Electronic communication signals are transmitted to the outside world in the form of electromagnetic radiation (i.e., TEMPEST phenomenon). An electromagnetic shielding room is an effective measure to ensure information security.

3. Basic Components of an Electromagnetic Shielding Room:

(1) Enclosure: Taking the welded steel plate electromagnetic shielding room as an example. It includes a six-sided skeleton frame and cold-rolled steel plates. The skeleton frame is made by welding channel steel and square tubes, with material specifications determined by the size of the shielding room. The ground beam (floor joist) should be insulated from the ground. The thickness of the cold-rolled steel plate for the walls is 1.5mm, which is first prefabricated into modules in the workshop and then welded to the inner side of the skeleton frame. All welding is done using CO2 shielded welding, with continuous full welding and a specialized leak detection device used to prevent wave leakage. All steel enclosures must undergo effective anti-rust treatment.

　　(2) Electromagnetic Shielding Door: The electromagnetic shielding door is the only moving component in the shielding room and a key factor in its comprehensive shielding effectiveness. It requires high technical content, special materials, and an extremely complex manufacturing process, with a total of 26 steps. There are two main types of electromagnetic shielding doors: hinged sliding doors and sliding doors. They come in various forms such as manual, electric, and fully automatic. Considering stability and cost-performance, the manual sliding hinged door (standard size 1900mm x 800mm) is the top choice. Elastic shielding strips should be installed at the connection points between the door and the door frame.

(3) Cellular Ventilation Waveguide Windows: Ventilation and air exchange, as well as air regulation, are essential facilities in shielding rooms. The cellular waveguide windows are composed of hexagonal steel waveguides with a side spacing of 5mm. These waveguides do not hinder air flow but effectively cutoff electromagnetic radiation. Currently, the main specification used is a fully welded cellular waveguide window of 300mm x 300mm x 50mm, with insertion loss of 150KHz to 1GHz greater than or equal to 100dB, fully meeting the requirements of the "Regulations." Shielding rooms are equipped with a corresponding number of waveguide windows based on their size, which are used for intake, exhaust, and pressure relief.

(4) Power and Signal Filters: Conduction electromagnetic interference is carried by conductors such as power lines and communication signal lines entering the shielded room, which must be filtered out with corresponding filters. Filters are passive bidirectional networks composed of passive components (inductors, capacitors), with the main performance parameters being cutoff frequency (low-pass, high-pass, band-pass, band-stop), insertion loss (band-stop attenuation), and the filter performance depends on the filter order (number of filter elements), and the filter structure type (single capacitor type C, single inductor type L, π-type).

(5) Waveguide: All non-conductive pipelines entering the shielded room, such as fire sprinkler pipes and optical fibers, should pass through a waveguide. The cutoff principle of the waveguide for electromagnetic radiation is the same as that of the waveguide window.

(6) Indoor Electrical and Decoration: Includes conduit wiring, distribution boxes, lighting, outlets, ceiling, wall decoration, and anti-static flooring for the floor. To ensure the stable operation of the shielding room, electrical and decorative materials must be selected that meet national standards for fire resistance, moisture resistance, and environmental protection.

4. Issues related to electromagnetic shielding room projects:

(1) Air Conditioning System: The air conditioning system for shielded rooms can be configured according to actual conditions. If central air conditioning is available, it can be directly connected through waveguide windows, or an individual air conditioner can be installed. The power cables for the air conditioner, the control signal lines between the indoor and outdoor units, and the gas water pipes must all undergo corresponding shielding treatment.

(2) Fire Alarm System: Electromagnetic Shielded Rooms should be equipped with a fire alarm system. Alarm signal lines and related control signals should also be separately filtered. Generally, one smoke detection alarm signal is configured.

(3) Grounding System: Due to the shell's leakage current during operation (related to the filter's working characteristics), the grounding requirement for the shielding room is extremely high. Single-point grounding is required, which is related to geological factors, with a grounding resistance ≤ 1Ω. A dedicated grounding wire of 10m² is mandatory.

(4) Power System: The power supply for the shielded room is typically configured with equipment power, air conditioning, and auxiliary lighting power as needed. Since there is some leakage from the casing during operation, the power supply for the protection room cannot pass through a leakage protector.

(5) Vibration Isolation: Communication rooms in civil defense and national defense command center projects all involve vibration isolation engineering, which has a close relationship with electromagnetic pulse protection rooms in terms of construction. Vibration isolation is divided into standard vibration isolation and simple vibration isolation.

　　(6) Air intake/exhaust ducts: The electromagnetic pulse protection chamber must be connected to the air intake/exhaust ducts, and installation can only be carried out after the ducts are properly installed.

5. Features:

Easy to assemble and disassemble with strong engineering, aesthetically pleasing, facilitates user relocation and expansion, avoiding redundant investments.

(2) Utilizes modular design with high-quality conductive liners between modules, securely fastened with bolts for reliable sealing.

(3) Modules are electrostatically powder-coated for easy installation and a stylish appearance.

6. Performance Specifications (Efficiency)

Test Frequency Band, Magnetic Field, Electric Field, Plane Wave, Microwave

     10KHz  150KHz  200KHz～50MHz  50MHz～1GHz  1GHz～20GHz   

Shielding Effectiveness ≥70dB ≥80dB ≥90dB ≥95dB ≥90dB

7. Product Application Range:

This product is a high-performance electromagnetic shielding room, suitable for instruments that require high electromagnetic shielding, such as product testing, testing, information security, computer networks, medical, and financial institutions.