Nuclear Magnetic Resonance (NMR) Shielding Room Solution
Application Field: Used in locations where MRI scanners may be subject to interference.
Performance Specifications:
( Tested according to GB/T 12190-2021 standard )
Insulation Resistance: > 3000 Ω
Ground Resistance: ＜1Ω
Relative Humidity: ≤80%
Atmospheric Pressure: 86～106 Kpa
Lumens: 100-150 lx
Shielding Performance: 10MHz ~ 100MHz > 100dB; Test Method in accordance with National Standard GB 12190-90.
Under the test circuit conditions of 1000pF coupled capacitors, the background noise is less than 2pC.
Lighting Power Supply Filters: 25A/220V, 2-way
Shell mechanical properties: Shielding body flatness ≤ 4 mm/M², shielding body perpendicularity ≤ 6 mm
Two-year deformation degree: Top indentation ≤ 8mm, Bottom indentation ≤ 3mm
Shielded Housing:
The lifespan of the shielding body is 20-30 years, and the seismic rating of the shielding shell is calculated at 8 levels. Considering the influence of the magnetic field.
Easy to assemble and disassemble, featuring a copper plate modular design.
Design of the bottom surface of the nuclear magnetic shielding room:
Shielding room at the placement location of the NMR instrument: 2.8m x 2.8m x 0.9m, the depth of other areas inside: 55cm
30 cm below grade, use C25 concrete for pouring. Level the concrete foundation with cement sand mortar, and apply double-layered SBM waterproofing.
Treat, lay high-intensity insulating flooring, followed by shielded ground assembly.
Shielding Room Shell Design: The shielding body is assembled using 0.35mm copper plate and high-quality pine wood frame (coated with fire-resistant paint), with modular assembly between modules.
Multi-layer copper mesh pads, secured with M6*100 stainless steel bolts.
Manual Single-Sided Shielding Door, Size: 1.2m wide × 2.1m high (externally swinging)
Based on the characteristics of the shielding room, a single-outer-opening shielding door is adopted. The shielding room door affects the overall shielding effect of the entire shielding room.
The most critical component is the weakest link in maintaining the overall performance of the shielding system, and it is the only movable part in the system.
Therefore, maintaining the stability of the shielding effectiveness of the shielding door is particularly important. The door structure is a single-panel swing door, with the door panel made of copper plates.
Wooden joists and stainless steel frames are welded together. The door frame edges are sealed with finger-type beryllium bronze spring strips, and magnet-free locks are used.
Observation Window: The observation window is lined with double-layered shielded glass and contains a 30-mesh copper mesh. The distance between the two copper meshes is 5-6 centimeters to enhance shielding.
Performance, guaranteed high clarity.
Grounding System: The grounding system of the shielding room employs a separate power grid grounding system, utilizing insulated flooring to isolate and connect to the system's zero potential.
Ground (using a grounding filter), with a requirement that the grounding resistance does not exceed 1Ω.
The waveguide window of the balanced ventilation system in the waveguide shield room uses a full-welded stainless steel mesh, with insertion loss consistent with the shield room.
Cooling pipes and superheat pipes to and from the isolation room are treated with stainless steel welded and tightened.
Electrical design and construction: Select appropriate cable diameters of power cables and different capacities of power filter based on the electrical load of each equipment.
Select a power filter with low leakage current, ensuring the insertion loss is consistent with the overall performance of the entire shielding room; the power supply within the room
Use conduit wiring and configure power outlets according to specified locations. The power connection can output 220V voltage, accommodating the needs of different equipment. The power supply passes through a filter into the shielding room, which requires crossing the room's wall. At the top of the shielding room, install DC LED lighting fixtures with no electromagnetic interference, providing an illuminance of 300 lux. The illuminance varies according to the installation height.
Determine the spacing of lighting fixtures reasonably. Ensure uniformity of indoor light blocking. To prevent interference from lighting equipment, the fixtures are powered by a power filter in the shielding room.
Installation Standards:
1. The moisture-proof layer employs welded seams, with the second layer placed over the center of the first layer's seam.
2. The ground PVC board insulation should be laid flat, neat, free of defects, and seamless.
3. Shield room modular assembly, dimensions must match the drawings, with wall perpendicularity error not exceeding 6mm.
4. Shield doors, observation windows, and conductive plates (with double suspended wires) must have a verticality error not exceeding 2.5 mm.
5. Interior wall finishing is smooth and aesthetically pleasing, with wall flatness not exceeding 4mm and wall perpendicularity not exceeding 5mm.
6. Indoor lighting wiring must be installed strictly according to the drawings; all wires must be routed through conduit, with both AC and DC entering the distribution box.
The electrical box should be clearly separated and labeled, with the red, black, and green wires for live, neutral, and ground clearly distinguished. No wires are allowed to pass through the magnet.
Overhead passage.
7. Equipment import must not be less than 2.8m (width) * 2.8m (height) with the bottom opening at ±0 level for easy entry of the magnet.
The body must be precisely positioned according to the drawings.
8. For floors that cannot sink, the wiring channels for interior decoration can be installed as exposed wiring channels.
9. Shielding insulation resistance less than 1KΩ.
10. Operate strictly according to the client's construction progress and quality standards.
Decorating Plan
The ceiling is made of micro-perforated aluminum ceiling tiles (600*600), both the main and secondary keels are made of aluminum, which may have a magnetic property.
2. The walls are finished with porous wooden sound-absorbing panels, offering a silent and aesthetically pleasing effect.
3. The ground is first treated with an epoxy self-leveling compound to ensure it is flat, sturdy, and durable. Subsequently, PVC (Polyvinyl Chloride) is then laid.
Kick molding treatment。
