Hitachi S-4800 manual Disturbance by Sound Waves, Site Requirements

1.1.9Disturbance by Sound Waves

Sound waves (vibrations of air) adversely affect the Model S-4800 regardless of their frequency and may cause image trouble. To prevent this, confirm before installation that equipment which may cause a sonic disturbance is not located in the vicinity of the S-4800. If such equipment exists, then check for noise level.

In general, as the frequency of noise increases, the sound pressure level decreases, and the frequency of noise varies depending on the cause of noise. It is therefore necessary to carry out noise frequency analysis at the installation location of the S-4800 SEM to check the degree of noise (effective factor) in each case.

Frequency : f (Hz)	Allowable Noise Level（Type I）		Allowable Noise Level (Type II）
ｆ≦150		75 dB or less	72 dB or less
1.1.10 Site Requirements		60 dB or less	60 dB or less
150≦ｆ≦800
800≦ｆ≦2000		54 dB or less	52 dB or less

1.1.10Site requirements

(1)Space required

A room of about 3.4 × 3.0 m is desirable.

(2)Minimum dimensions of entrance 0.95 (W) × 1.7 (H) m

(3)Durability of floor

Floor loading capability (kg / m2 )	≥	Total mass of equipment (kg)
3		Floor area of the room (m2 )

(4)Instrument layout

See Fig. 1-2 for the layout example.

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