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“Uncertainty-noise” Le Mans
11
Acoustique
&
Techniques n° 40
t is at the international level and in the field of
standardization that uncertainty emerged as a key issue in
the 1990s. The reason is that measurement methods fall well
in with standardization and markets are now worldwide. At the
European market level, the Technical Board (BT) of CEN has
set up in 2000 its WG 122 “Uncertainty of measurements”
to investigate the issue in European standards, with the aim
to providing a coherent methodology across sectors to
ensure a reliable interpretation of measurement results. The
Group made recommendations on how to develop guidance
for CEN technical committees. An important seminar was
held in 2002. The outcome of the whole exercise was a
document “Implementation of the concept of measurement
uncertainty in European standards” and CEN technical bodies
were asked, when possible, to implement the guidance and
recommendations given in that document.
The initial CEN BT resolution
The decision that guidance should be given to standardizers on
how to address uncertainty in European standards was taken
by CEN BT (Technical Board) in April 2003. The resolution is
reproduced hereafter.
Resolution BT 21/2003
Subject
: Report of BT/WG 122
BT,
- gratefully acknowledging the important efforts made by CEN/
BT WG 122 «Uncertainty of Measurement» in researching this
topic on behalf of CEN;
- recognizing the positive contribution made by the successful
seminar held in 2002;
- appreciating the recommendations and proposals made by
CEN/BT WG 122;
- noting the report (BT N 6831) and its recommendations; -
decides,
- to ask CEN technical bodies and other relevant bodies
to be aware of the guidance and recommendations contained
in that report;
- to ask CEN technical bodies, when possible and
necessary,
to implement the guidance and recommendations within the
limits allowed by available resources
and without compromising the need to deliver European
Standards as quickly as possible;
- that the BOSS will be complemented accordingly.
This Resolution is applicable as from: 2003-04-24
A technical and political challenge
The now widely recognized need to deal with uncertainty
in measurement standards has brought an extra burden
to standardizers. On the one hand, the issue is technically
difficult and it has sensitive political side-aspects. Reaching
a consensus when drafting a standard is always a complex
matter. Adding the uncertainty issue is making it even harder.
On the other hand, it is common knowledge that it takes too
long to draft standards and rules are presently enforced (at
national, European and international levels) to reduce drafting
time down to 3 years. Including one more technically and
politically sensitive topic and at the same time shortening the
time-scale is a challenge. The CEN guidance was written with
these contradictory requirements in mind.
Dealing with uncertainties in european
standards
Jean Jacques
INRS
Mission Normalisation,
30, rue Olivier Noyer
75680 Paris CEDEX 14
FRANCE
“Uncertainty” should have always been a key word in the field of standardization as many
standards are devoted to providing methods for measuring quantities of all kinds. However, it
is only relatively recently that it was realized that all metrological standards should absolutely
and systematically deal with uncertainties. This resulted in specific guidance given in 2004
at the European level on the “uncertainty of measurement concept in European Standards”
provided by CEN (the European Standardization Committee) to all those contributing to the
drafting of European standards. This paper reports about this guidance that applies to all
fields of metrology and, in particular, to acoustics.
L’incertitude devrait toujours avoir été un mot clé dans le domaine de la normalisation puisque
les normes sont destinées à fournir des méthodes de mesure pour toutes sortes de choses.
Toutefois, ce n’est que relativement récemment qu’on a pris conscience que toutes les
normes en métrologie devraient absolument et systématiquement prendre en compte les
incertitudes. Cela a abouti à un guide spécifique paru en 2004 au niveau européen sur «le
concept d’incertitude de mesure dans les normes européennes» produit par le CEN pour tout
ceux qui contribuent à éditer des normes européennes. Cet article présente ce guide qui
s’applique à tous les domaines de la métrologie et en particulier, à l’acoustique.
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