Manual

239
Appendix
L
EX
Noise Exposure Level LEX
The Noise at Work Directive 2003/10/EC lays down minimum re-
quirements for the protection of workers from risks to their health
and safety arising or likely to arise from exposure to noise and in
particular the risk to hearing.
Steady noise L•
EX,8h
= L
Aeq
: (applies to L
AS,
deviation < 5 dB
)
L
Aeq
measured over a short time equals L
EX,8h;
the following
formula applies for a measurement period < 8 hours: L
EX,8h
=
L
Aeq
+ 10 x log ( T / 8 hours )
Steady noise with stepped level variations: •
Measure L
Aeq
at the different levels and enter the data with
the corresponding exposure time in the NTi Audio noise expo-
sure level post-processing form; the L
EX,8h
will be calculated
and displayed.
Varying noise levels: •
L
EX,8h
= L
Aeq
measured for 8 hours
The exposure limit values and respective actions are:
L
EX, 8h
L
Cpeak
Action
Lower limit value 80 dB(A) 135 dB The employer shall make individual hearing protectors available
to workers
Upper limit value 85 dB(A) 137 dB Hearing protectors shall be used
Exposure limit 87 dB(A) 140 dB The attenuation characteristics of the hearing protectors worn
must adequately reduce the levels below this limit
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