Basic structural 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, which require a tight electromagnetic seal. Corresponding shielding treatments are also applied to all incoming and outgoing pipelines to block the entry and exit of electromagnetic radiation.

　  (2) There are three main types of electromagnetic shielding rooms: steel plate assembled, steel plate welded, and copper mesh. The assembled type is made by assembling modules with walls of 100mm thickness from 1.2mm steel plates, which is relatively simple in production and installation, suitable for small areas and projects with low shielding performance requirements. It can be disassembled and relocated, but the shielding performance will significantly decrease after relocation. The steel plate welded type shielding room is made by welding 1.2mm cold-rolled steel plates with a frame, offering high shielding performance and adaptable to various specifications and 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, thereby enhancing the accuracy of testing results.

(2) Block the spread of electromagnetic radiation indoors to the outside. 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 the staff.

(3) Prevent information leakage from electronic communication equipment to 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 skeletal frame, cold-rolled steel plates. The skeletal frame is made of channel steel and square tubes welded together, 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 inside of the skeletal frame. All welding is done using CO2 shielded welding, with continuous full welding and leak detection using special equipment to prevent wave leakage. All steel enclosures must undergo excellent 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 the room's comprehensive shielding effectiveness. It has a high technical content, uses special materials, and involves 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, each available in manual, electric, and fully automatic configurations. Considering the stability and cost-performance ratio, the manual sliding hinged door (standard door: 1900mm x 800mm) is the first 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 shielded rooms. The cellular waveguide windows are composed of hexagonal steel waveguides with a side distance of 5mm. These waveguides do not obstruct air flow but provide cutoff action against electromagnetic radiation. Currently, full-welded cellular waveguide windows with a specification of 300mm x 300mm x 50mm are predominantly used, with insertion loss of 150KHz to 1GHz being ≥100dB, fully meeting the requirements of the "Regulations." 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) AC/DC Filters: Power lines and communication signal lines entering the shielding room carry conducted electromagnetic interference. Corresponding filters must be used to eliminate it. Filters are passive bidirectional networks composed of passive components (inductors, capacitors). Their main performance parameters include cutoff frequency (low-pass, high-pass, band-pass, band-reject), insertion loss (band-stop attenuation), and the filter performance depends 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 shielding 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 pipe wiring, distribution boxes, lighting, power outlets, ceiling installation, wall decoration, and anti-static flooring for the floor. To ensure the stable operation of the shielded 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 the shielding room 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 lines for the air conditioner, the control signal lines for the indoor and outdoor units, and the gas and water pipes must all undergo corresponding shielding treatment.

(2) Fire Alarm System: Electromagnetic shielding rooms should be equipped with a fire alarm system. Alarm signal lines and related control signals should be filtered separately. Typically, one smoke alarm signal is configured.

(3) Grounding System: Due to the shell's leakage during operation (related to the filter's operating characteristics), the grounding requirement for the shielding room is extremely high. 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 from the casing during operation, the power supply for the protective room cannot pass through a leakage protector.

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

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

5. Features:

(1) Easy to assemble and disassemble with strong craftsmanship, aesthetically pleasing design, user-friendly for relocation and expansion, and cost-effective to avoid redundant investments.

(2) Modular design with high-quality conductive liners between modules, securely bolted and sealed for reliable performance.

(3) Modules are electrostatically powder-coated for easy installation and a sleek, attractive 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 with high electromagnetic shielding requirements, such as product testing, testing, information security, computer networks, medical, and financial institutions.