Casella-cel CEL-281 Manual do Utilizador descarregar pdf (Página 29)

2.2.5 Noise Dose

Noise dose is not an absolute measurement but a percentage of the rec-

ommended maximum daily personal noise exposure.

In this way, 100% noise dose will be equal to the exposure limit for the

person, while values lower than 100% indicate a lesser exposure than

the allowable dose and values above 100% show excessive exposure.

The Daily Sound Exposure (E

) is the total A-weighted sound expo-

sure sustained in a "typical working day", while the

aily Sound Expo-

sure Level (L

) is the E expressed as an equivalent continuous

sound level (L

) over a normalised working day of eight hours.

The formula for equivalent continuous sound level L is:

= 10 log

∫

(

) dt

Which for a normalised 8 hour day becomes:

= 10 log

(P )

Where:

= 8 hours,

= 2x10 Pa

Therefore the formula can be re-written as:

= 10 log E + 85 (dB)

_Introduction

1 2 ... 24 25 26 27 28 29 30 31 32 33 34 ... 146 147

Sem comentários

Casella-cel CEL-281 Manual do Utilizador Página 29