Bruker AVANCE, User Manual

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Environment and Site Survey Measurement
H157655_1_008 45
Criterion
Curve
Amplitude µm/s
(11µi/s)
*
Description of Use
Residential day
(ISO) 200 (8 000)
Barely perceptible vibration. Appropriate to sleep
areas in most instances. Usually adequate for
computer equipment, hospital recovery rooms.
semiconductor probe test equipment, and
microscopes less than 40x.
Operating
theater (ISO) 100 (4 000)
Vibration not perceptible. Suitable in most
instances for surgical suites, microscopes to 100x
and for other equipment of low sensitivity.
VC-A 50 (2 000)
Adequate in most instances for optical microscopes
to 400x, microbalances, optical balances, proximity
and projection aligners, etc.
VC-B 25 (1 000)
Appropriate for inspection and lithography
equipment (including steppers) to 311m line widths.
VC-C 12.5 (500)
Appropriate standard for optical microscopes to
1000x, lithography and inspection equipment
(including moderately sensitive electron
microscopes) to 1 11m detail size, TFT-LCD
stepper/scanner processes.
VC-D 6.25 (250)
Suitable in most instances for demanding
equipment, including many electron microscopes
(SEMs and TEMs) and E-Beam systems.
VC-E 3.12 (125)
A challenging criterion to achieve. Assumed to be
adequate for the most demanding of sensitive
systems including long path, laser- based, small
target systems, E-Beam lithography systems
working at nanometer scales, and other systems
requiring extraordinary dynamic stability.
VC-F 1.56 (62.5)
Appropriate for extremely quiet research spaces;
generally difficult to achieve in most instances,
especially cleanrooms. Not recommended for use
as a design criterion, only for evaluation.
VC-G 0.78 (31.3)
Appropriate for extremely quiet research spaces;
generally difficult to achieve in most instances,
especially cleanrooms. Not recommended for use
as a design criterion, only for evaluation.
*As measured in one-third octave bands of frequency over the frequency range 8 to 80
Hz (VC-A and VC-B) or 1 to 80 Hz (VC-C through VC-G).
The information given in this table is for guidance only. In most instances, it is
recommended that the advice of someone knowledgeable about applications and
vibration requirements of the equipment and processes be sought.
Source: Reprinted with permission from Colin Gordan Associates.
Table 7.1: Application and Interpretation of the Generic Vibration Criterion (VC) Curves