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. Additionally, all incoming and outgoing pipelines are appropriately shielded to further 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 constructed from 1.2mm steel plates, cut into modules of 100mm thickness, and assembled together. It has a simple production and installation process, suitable for small areas and 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 made by welding 1.2mm cold-rolled steel plates to a skeleton frame, offering high shielding effectiveness and adaptable to various sizes, making it the primary form of electromagnetic shielding rooms. The copper mesh type is used for simple 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 dark room) to simulate an ideal electromagnetic environment, enhancing the accuracy of testing 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 protect 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), and 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 of channel steel and square tube welding, with material specifications determined by the size of the shielding room. The ground beam should be insulated from the ground. The cold-rolled steel plate thickness of the walls is 1.5mm, which is pre-fabricated into modules in the workshop and then welded on the inside of the skeleton frame. All welding is done using CO2 shielded welding, with continuous full welding, and checked for leaks using special equipment to prevent signal leakage. All steel enclosures must undergo good anti-rust treatment.

　　(2) Electromagnetic Shielding Door: The electromagnetic shielding door is the only moving part in the shielding room and a key factor in the room's overall shielding effectiveness. It boasts a high level of technology, uses special materials, and has an extremely complex manufacturing process, with a total of 26 steps. The electromagnetic shielding door is divided into two main types: hinged sliding doors and sliding doors, each available in manual, electric, and fully automatic versions. Considering the stability and cost-effectiveness of use, the manual sliding hinged door (standard door size: 1900mm x 800mm) is recommended first. 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 shielded rooms. The cellular waveguide windows are composed of hexagonal steel waveguides with side gaps of 5mm. These waveguides do not obstruct air flow but effectively block electromagnetic radiation. Currently, the 300mm x 300mm x 50mm full-welded cellular waveguide windows are predominantly used, with insertion loss of 150KHz to 1GHz ≥ 100dB, fully meeting the requirements of the specification. Shielded 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 by 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 filter performance depending on the filter order (number of filter components), filter structure type (single capacitor type C, single inductor type L, π type), etc.

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

(6) Indoor Electrical and Decoration: Includes pipeline wiring, distribution boxes, lighting, outlets, ceiling, wall decoration, and anti-static floorings. To ensure the stable operation of the shielding room, electrical and decoration materials must be selected in compliance with national standards for fire prevention, moisture resistance, and environmental protection.

4. Electromagnetic Shielding Room Engineering Issues

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

(2) Fire Alarm System: The electromagnetic shielding room should be equipped with a fire protection system. Alarm signal lines and related control signals should also be filtered separately. Generally, one smoke alarm signal is configured.

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

(4) Power System: The power supply for the shielding room is typically configured with equipment power, air conditioning lighting auxiliary power as needed. Due to a certain amount of leakage in the casing during operation, the power supply for the protective room cannot pass through a leakage protector.

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

　　(6) Air intake and exhaust ducts: The electromagnetic pulse protection room should be connected to the air intake and exhaust ducts, and installation can only take place after the ducts are properly laid.

5. Features:

(1) Easy to assemble and disassemble with strong assembly and disassembly techniques, aesthetically pleasing, convenient for relocation and expansion, and prevents redundant investment.

(2) Utilizing modular design, superior conductive linings are incorporated between modules, securely fastened with bolts and sealed for reliable performance.

(3) Modules feature electrostatic powder coating for easy installation and a sleek, stylish appearance.

6. Performance Metrics (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 requiring stringent electromagnetic shielding, such as product testing, testing, information security, and units in computer networks, medical, and financial sectors.