Hitachi S-4800 manual Floor Vibration, Allowable Vibration, Vibration Allowable Amplitude X, Y

remains unaffected so far as the field strength is within a few ten µT.

8.The allowable values given in Table 1-1 are applicable at the specified working distances (4 mm at accelerating voltage 15 kV and 1.5 mm at 1 kV). At a longer working distance, the allowable value of stray magnetic field becomes smaller. (Namely, image is apt to be affected by stray magnetic field.)

1.1.7Floor Vibration

You should measure the floor vibration at the place for installing the Model S-4700 in advance. When the requirements given in Table 1-2 are satisfied, no image trouble will occur.

If the instrument is installed on the first floor in a reinforced concrete or steel frame building, the instrument performance will not be degraded by external vibrations so long as vibration sources such as heavy-duty machine tools or transportation facilities (electric car, for example) are not operated nearby.

Table 1-2 Allowable Vibration

Floor vibration: Image trouble will not be observed when the conditions below are satisfied. S-4800 Type I

Vibration	Allowable Amplitude (X, Y)
Frequency
(Hz)	(∝m Peak to Peak)
1.0	Less than 7.0
1.4	Less than 2.0
2.0	Less than 2.0
3.0	Less than 4.0
4.0	Less than 4.5
5.0	Less than 4.5
6.0	Less than 4.0
10.0	Less than 3.0

Vibration	Allowable Amplitude (Z)
Frequency
(Hz)	(∝m Peak to Peak)
1.0	Less than 25.0
2.0	Less than 14.0
3.0	Less than 5.0
3.5	Less than 2.9
4.0	Less than 1.8
5.0	Less than 1.0
6.0	Less than 1.1
10.0	Less than 1.2

S-4800 Type II

Vibration	Allowable Amplitude (X, Y)
Frequency
(Hz)	(∝m Peak to Peak)
1.0	Less than 8.0
1.5	Less than 3.0
2.0	Less than 1.4
2.4	Less than 1.4
3.0	Less than 3.0
5.0	Less than 4.0
6.0	Less than 3.5
10.0	Less than 3.5

Vibration	Allowable Amplitude (Z)
Frequency
(Hz)	(∝m Peak to Peak)
1.0	Less than 20.0
2.0	Less than 10.0
3.0	Less than 5.0
4.0	Less than 2.7
5.0	Less than 1.8
6.0	Less than 1.0
7.0	Less than 1.0
10.0	Less than 1.0

NOTICE: The allowable amplitude corresponds to an image deviation of less than 0.2 mm

on a 5 inches x 4 inches size micrograph at magnification 220,000× .

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