The shielded room is a modern protective device specially designed and constructed to prevent the human body from being harmed by radar microwave radiation. The shell is assembled with high-quality cold-rolled galvanized steel modules, and is equipped with electromagnetic leakage shielding doors, special ventilation waveguide windows, transmission and fire-fighting waveguides. The observation window is specially made of imported ultra-fine silver-plated copper wire cloth and cesium potassium fireproof glass, which has a good perspective effect. The radar microwave radiation leakage value of the shielded room fully meets the limit standard and is higher than the national public exposure limit standard. , It can effectively protect the human body working and visiting nearby.
The national standard overview of shielded room is:
National Bureau of Secrets: "Technical Requirements and Test Methods for Electromagnetic Shielding Rooms for Handling Confidential Information" BMB3-1999. This standard divides the shielding rooms into Class C and Class B. Class C shielding rooms have high shielding effectiveness.
Chinese People's Liberation Army: "General Technical Requirements and Inspection Methods for Military Electromagnetic Shielding Rooms" GJBz20219-94 military standard is also divided into C-level and B-level, and C-level shielding rooms have the highest shielding effectiveness.
National Defense and Civil Air Defense of the Chinese People's Liberation Army: "Design Code for Electromagnetic Pulse Protection of Protective Engineering" GJB3928-2000, "Design Code for Electromagnetic Pulse Protection of People's Air Defense" RFJ-2001. Test basis: "Measurement Method of Shielding Effectiveness of High-Performance Shielding Room".
The shielding room is made of magnetic materials. The parameter to measure the magnetic permeability of the material is permeability. The higher the permeability, the better the shielding effect. The common common high-permeability material is cold-rolled steel plate, and the thickness of the shield plays a decisive role. The stronger the magnetic field, the thickness of the shielding material should increase accordingly.
The dispute between unshielded wiring and shielded wiring in shielded rooms has a history of many years. With the demand for communication systems, especially the maturity of the theory of integrated wiring systems, the industry has gradually formed a consensus on this issue: unshielded systems and shielded systems have their own Directors have their own more suitable places.
The principle of the shielded room is that a shielded system (shielded room, shielded computer room) composed of shielded cables and shielded components will be the best choice. Through interference and eavesdropping experiments, divergence tests, bit error rate tests, and anti-interference experiments, in order to make the network safe and reliable and have excellent anti-interference performance, shielded cables and components must be selected.
The main function of the shielded room is to isolate the electromagnetic interference from the outside world and ensure the normal operation of indoor electronic and electrical equipment. Especially in the measurement and testing of electronic components and electrical equipment, the electromagnetic shielding room (or dark room) is used to simulate the ideal electromagnetic environment to improve the accuracy of the detection results. The shielding room blocks indoor electromagnetic radiation from spreading to the outside world, and strong electromagnetic radiation sources should be shielded and isolated to prevent interference with the normal operation of other electronic and electrical equipment and even damage the health of the staff.
The shielded room prevents information leakage of electronic communication equipment and ensures information security. Electronic communication signals will spread to the outside world in the form of electromagnetic radiation (ie TEMPEST phenomenon), and the enemy can intercept and restore them by using monitoring equipment. The electromagnetic shielding room is an effective measure to ensure information security.