Newport Spectra-Physics ST-200, Руководство пользователя

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2 General Information
2.1 Introduction
The Smart Table is a combination of the structurally damped vibration
isolation table with electronics that can monitor vibration in real time and
active elements that use the vibration data to suppress the vibration.
Vibration state of the optical table is an important characteristic, in many
cases defining its suitability for a task at hand. Reducing vibration, especially
the dynamic deviation of the table from a rigid-body type behavior, is one of
the most important criterions of the table design. It is achieved mainly by the
vibration isolation. Vibration isolation by passive isolating legs, such as
Newport I-2000, reduces the vibration transmitted to the table from the floor.
Although excellent isolation from floor vibration can be achieved in these
systems, the table will deviate from the ideal rigid-body behavior at natural
frequencies of its flexural vibrations. External sources acting on the tabletop
(air turbulence or acoustical waves) or the dynamic events generated in the
payload excite resonance vibration in the table’s own free-state modes such
as bending and torsion. This can lead to deterioration of the payload
performance, in particular, misalignment of the optical equipment.
The Smart Table includes two active vibration dampers that add dissipation
to all natural vibration modes of the table in a wide frequency range without
creating any additional resonances at lower frequencies. If the load on the
table changes, the dampers maintain their efficiency and stability after simple
auto-tuning of control gains.
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