详情描述

Low-frequency magnetic shielding room for cathode luminescence systems, scanning electron microscope equipment, transmission electron microscope equipment, material analysis equipment, and other precision instruments.

Basic Requirements

The laboratory will be comprised of an air cylinder room, a changing room, a air shower room, and a clean room, with the construction meeting the instrument manufacturer's installation requirements for equipment.

The site laboratory report indicates that the DC magnetic field exceeds the standard, necessitating the implementation of a passive magnetic shielding system.

Basic engineering design principles: 1) Rational structure, materials must be energy-saving, environmentally friendly, flame-retardant, and corrosion-resistant; 2) Adhere to the people-oriented principle, ensuring the overall aesthetics of the laboratory; 3) Stable and reliable system, easy for daily maintenance and repair.

The laboratory construction must be completed.

  1. Ensure the alternating magnetic field inside the electron microscope room is between 10 Hz and 1 KHz, with an amplitude of <1mG (peak-to-peak), and the direct current magnetic field changes by less than 0.5mG within 5 minutes, while fully considering the impact of subsequent magnetic field changes.
  2. Ensure electron microscope room noise levels: 20-120Hz < 52dB, 120-450Hz < 43dB, above 450Hz < 47dB
  3. 3. Ensure indoor vibration: Horizontal vibration with vibration frequency between 0-10Hz, vibration rate < 7 um/sec; vibration frequency between 10-60Hz, vibration rate < 15 um/sec; vibration frequency above 60Hz, vibration rate < 20 um/sec.
  4. Vibration in the vertical direction with frequencies between 0-10Hz, vibration rate < 6um/sec; between 10-60Hz, vibration rate < 20um/sec; above 60Hz, vibration rate < 30um/sec.
  5. 4. The ground must not be paved with steel plate under the electron microscope main unit, and should be sturdy, durable, and easy to maintain.
  6. 5. Detailed descriptions of the key technologies for laboratory magnetic shielding control are required.
  7. 6. Ventilation and air conditioning systems provided, meeting the requirement for indoor constant temperature (environmental temperature: 21°C +/- 4°C, stability: 0.5°C/h), low noise level, and durability.
  8. 7. The laboratory door width and height should meet the requirements for equipment entry.
  9. 8. The power supply for the electron microscope main unit should be a 220V single-phase three-wire system without leakage protection, featuring a 25A current with an independent switch.
  10. Magnetic shielding decorative section:
  11. 1. The main shielding shell is constructed using a high permeability material welding structure to form a hexahedral magnetic shielding shell.
  12. 2. Low-carbon shielding steel plate (magnetized degaussing treated) requires continuous full welding, and the structural housing needs double-sided welding.
  13. 3. Rib: Welded with square steel for support; the beam is reinforced with square steel welding.
  14. 4. Welding Method: Full penetration welds are used between panels.
  15. 5. The structure is assembled on-site. Based on the site conditions and technical requirements of the drawings, assembly and lifting plans are formulated to ensure engineering and technical quality.
  16. 6. After the steel plate is processed and trimmed, it must undergo specialized anti-magnetic treatment before it can be transported to the construction site.
  17. Anti-vibration section:
  18. 1. Vibration isolation base for waveguide. Active damping equipment as a backup solution.
  19. 2. The quality of the concrete shock-absorbing foundation is determined by the specific ground conditions. The concrete shock-absorbing pad should be connected to the outside world through a "soft connection."