详情描述

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

Basic Requirements

The laboratory will be composed of an air bottle room, a changing room, a blow-off room, and a clean room, with the construction meeting the instrument manufacturers' requirements for equipment installation.

Based on the site laboratory report, the DC magnetic field has exceeded the standard, and a passive magnetic shielding system is required.

Engineering design fundamentals include: 1) Reasonable structure, with selected materials being energy-efficient, environmentally friendly, flame-retardant, and rust-proof; 2) Adhering to the principle of people-oriented design, ensuring the overall aesthetics of the lab; 3) System stability and reliability for easy daily maintenance and repair.

Upon completion of the laboratory construction, the following requirements must be met:

  1. Ensure the AC magnetic field inside the electron microscope room: frequency between 10 Hz to 1 kHz, <1mG (peak-to-peak), DC magnetic field: change less than 0.5mG within 5 minutes, and fully consider the impact of subsequent magnetic field changes.
  2. Ensure electron microscope room noise: 20-120Hz < 52dB, 120-450Hz < 43dB, above 450Hz < 47dB
  3. 3. Ensure indoor vibration: For horizontal vibration, 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 vertically with frequencies ranging from 0 to 10 Hz, vibration rate < 6 um/sec; frequencies between 10-60 Hz, vibration rate < 20 um/sec; frequencies above 60 Hz, vibration rate < 30 um/sec.
  5. 4. The ground requirements are that there should be no steel plate laid under the electron microscope main unit, and it must be sturdy and durable, easy to maintain.
  6. 5. Detailed descriptions of the key technologies for laboratory magnetic field shielding control are required.
  7. 6. Supply ventilation and air conditioning systems that meet the indoor constant temperature requirements (environmental temperature: 21°C +/- 4°C, stability: 0.5°C/h), low noise, and durable.
  8. 7. The laboratory door width and height should meet the requirements for the entry of equipment.
  9. 8. The power supply for the electron microscope main unit should be 220V, single-phase three-wire, without leakage protection, and equipped with a 25A current supply 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 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 welding is 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 for cutting, it must undergo specialized anti-magnetic treatment before it can be transported to the construction site.
  17. Vibration Damping Section:
  18. 1. Vibration isolation method of the waveguide base. Active damping equipment as a backup solution.
  19. 2. The quality of the concrete shock-absorbing foundation is determined by the specific foundation conditions. The concrete shock-absorbing pad should be connected to the outside world through a "soft connection."