The pneumatic acoustic enclosure mainly relies on compressed air drive + physical sound insulation & absorption + tight sealing to achieve noise isolation and quiet testing environment. Its working principle can be divided into four parts:

1. Pneumatic Opening & Closing Mechanism

• Powered by compressed air (0.4–0.8 MPa), the cylinder pushes the box cover / door to open and close automatically.

• The cylinder provides sustained pressure to press the door tightly against the frame, ensuring no sound leakage during testing.

• Equipped with solenoid valves, it can be controlled manually or linked with PLC / test equipment for automatic operation.

2. Sound Insulation Principle (Block Noise Transmission)

• The box body adopts a double-layer or thickened steel plate structure, with sound-absorbing cotton / damping materials filled in the middle.

• Using the principle of impedance mismatch, it reflects and blocks external high-noise interference from entering the test area.

• This reduces the external noise by about 30–45 dB before it reaches the internal test space.

3. Sound Absorption Principle (Eliminate Internal Echo)

• The inner wall is covered with sound-absorbing cotton, wedge-shaped absorbers or perforated panels.

• Internal noise and echoes generated by the tested product are converted into heat energy through porous materials and eliminated.

• This avoids standing waves and reverberation, ensuring accurate noise test results.

4. Sealing & Vibration Isolation Principle

• The door frame uses elastic sealing strips to prevent sound leakage through gaps.

• The bottom is equipped with damping pads to isolate vibration noise transmitted from the ground or equipment.

• Combined with sealed cable glands, it maintains a stable low-noise environment inside the box.

Simplified Summary

The pneumatic acoustic enclosure uses cylinders to automatically close and tightly seal the box, blocks external noise through a multi-layer sound insulation structure, absorbs internal echoes with sound-absorbing materials, and finally forms a stable quiet environment for product acoustic and noise testing.