Active Vibration Isolation Systems
The measured vertical floor vibration exceeded the floor vibration specification VC-D below 10 Hz and 16 Hz. The DVIA-T45
active vibration isolation system reduced the vertical floor vibration from VC-B to VC-E.
Generic Vibration Criteria
Criterion Curve
Description
Amplitude μm/s (µin/s)
Detail Size μm
Workshop (ISO)
Distinctly perceptible vibration. Appropriate to workshops and non-sensitive areas.
800 (32,000)
N/A
Office (ISO)
Perceptible vibration. Appropriate to offices and non-sensitive areas.
400 (16,000)
N/A
Residential Area (ISO)
Barely perceptible vibration. Appropriate to sleep areas in most instances.
200 (8,000)
75
Operating Theatre (ISO)
Vibration not perceptible. Suitable for surgical suites, microscopes to 100x.
100 (4,000)
25
VC-A
Adequate for optical microscopes to 400x, microbalances, optical balances.
50 (2,000)
8
VC-B
Appropriate for inspection and lithography equipment to 3μm line widths.
25 (1,000)
3
VC-C
Appropriate for optical microscopes to 1000x, lithography equipment to 1μm.
12.5 (500)
1 - 3
VC-D
Suitable for demanding equipment including electron microscopes (SEMs/TEMs).
6.25 (250)
0.1 - 0.3
VC-E
For the most demanding systems including E-Beam lithography at nanometer scales.
3.12 (125)
< 0.1
VC-F
For extremely quiet research spaces. Not recommended as design criterion.
1.56 (62.5)
N/A
VC-G
For extremely quiet research spaces. Not recommended as design criterion.
0.78 (31.25)
N/A
Notes:
1. VC-A/B is measured in 1/3 octave bands from 8-80 Hz, VC-C through VC-G from 1-80 Hz.
2. Detail size refers to line widths in microelectronics manufacturing or particle sizes in medical research.
