Volume 6, Number 4, December, 1998 - Noise News International

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Characteristic Machine Parameter ---4
L1 andl2 describe twodifferent qualities of noisecontrolpertormance.
Mac~lines withan emission whichis lowerthanl2 havea higherquality
in respectof noisethanthoselowerthan L1.
Fig. l. Emission value rangevs. emission levels, according
to EN ISO 11689
Results
If consistently applied, the standardization concept
specific to machinery can facilitate the reduction
of levels of noise at the workplace. All sound
sources should be included if possible; not only
machines, but also machine elements, tools, and
operating procedures.
The availability of noise emission data for machinery
is, among other things, necessary for the
standardization concept to function. It is therefore
necessary at the European level to compile noise
emission data, at least for selected machines. The
emission value range should be included in safety
standards (C standards) specific to machinery. Current
sound emission data should be made available
to potential customers in a European database.
Moreover, an effective
method of estimating
noise levels at the
workplace (noise prediction)
is necessary in
order for this standardization
concept to function
properly. Based on
existing standards
(VDI 3760, ISO TR
11690-3), both simplified
methods of predie
ting noise and those
which take account of
complex operating situations
need to be developed
further.
State of the Art
The term "state of the
art" is used in ED direc-
Table 3: Need for standardization in occupational health and safety
and machine safety (1 =low need, 2 =medium, 3 =high)
Object of standardization
Emission Transmission Immission Definitions,
Standardization Sound sources: Sound Workrooms Wlp1ace, measuring
content machines, tools insulation Worksites Work-station. equipment,
operating procedures
meas'rnent
methods.
Framlwrk Machinestndrds.
specific Buildings
standards
Definition
measuringmethods
for noise parameters
112 2 2 I 2 I
Presentation of the
range of noise 1 3 2 1 2 2
parameters
Achievable values
(state of the art)
Examples of
low-noise design
Total number of
standards (approx.)
tives and national regulations to describe requirements
for technical systems without having to provide
far-reaching technical details. This is intended
to take account of the complexity, rapid development,
and wide variety of technical systems. Ifregulations
require compliance with the state of the art, it
means that the current state for a high-quality technical
concept or technical product must be considered
(see EN 45020,18 EN 292-1).
In noise control standards, the term "state of the art
for noise control" is avoided. Instead, standards refer
to the acoustic quality or the acoustical performance
of a technical product. It can generally be assumed
that a high acoustic performance as described in a
standard is equivalent to the state of the art (for the
purposes of regulations). This means that criteria for
quality described in standards remain a flexible tool
for describing products and technical measures. Standards
can serve as the basis for assessing the state of
the art. They do not contain a positive or negative assessment.
The assessment of machinery with regard
to the state of the art remains a separate procedure
which is only used to make sure that there is compliance
with the requirements of regulations.
Need for Standardization
The study mentioned at the beginning of this article
established the need for standardization for individual
work system elements. These needs are quantified
in Table 3.
Need for Standardization for Machines
and Other Sound Sources
In general, the framework standards for establishing
noise emission and for reducing noise from machines
1 3 3 2 3 2
2 2/3 1 1 2 1
30 400 50 70 30 40 60
2
1998 December
NoiselNews International 205