Tools of the trade - Vol 18 - Thorlabs - #73

Active Isolation Systems (continued)

Vertical Damping is achieved by the use of a dual-chamber damped pneumatic spring. The table is supported by the air pressure in these chambers. A piston, clamped to the bottom of the table, is sealed to the upper chamber with a rolling rubber diaphragm, allowing virtually friction-free motion between piston and chamber. Floor or tabletop motion forces air to flow from one chamber to the other through a high resistance damper. This restriction of airflow damps oscillatory motion between the floor and table, dramatically reducing settling time. The volume ratio of the chambers has been optimized to maximize damping performance for our complete range of tabletops while preserving a low resonant frequency.

Horizontal Damping is accomplished by supporting the pneumatic vertical isolator on a trifilar suspension system. This innovative pendulum design uses gravity to provide the restoring force after horizontal disturbances. Horizontal oscillations at the system's resonant frequency are damped by linking the base of the vertical isolator to the outer cylinder with an oil-free vibration-absorbing damper.

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^Performance values were measured supporting a 1.25m x 2.5m x 310mm (4' x 8' x 12.2") table. Heavier tables or loads will have a lower vertical resonant frequency, higher transmissibility at resonance, and lower transmissibility at 10 Hz.

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Air Compressors

For laboratories not equipped with a compressed air supply, Thorlabs provides a low noise air compressor that is self-contained, lightweight,

and compact. Due to the low noise emitted (35dB at 1m) the compressor will not interfere with sensitive experiments. Each system

includes its own air regulator, filter and receiver tank with pressure gage,

safety valve, drain and line pressure gage.

Sales: 973-579-7227