# Regulation (EC) No 1222/2009 of the European Parliament and of the Council of 25 November 2009 on the labelling of tyres with respect to fuel efficiency and other essential parameters (Text with EEA relevance), Division 5: REQUIREMENTS APPLICABLE TO CANDIDATE LABORATORIES

Extent: E+W+S+N.I.

Candidate laboratories shall repeat the alignment procedure at least once every two years and always after any significant machine change or any drift in machine control tyre monitoring data.
A common set of five different tyres, conforming to the specification of section 2.2 shall be measured in accordance with section 2.3 by the candidate laboratory and by one reference laboratory. More than five alignment tyres may be tested at the request of the candidate laboratory.
The alignment tyre set shall be provided by the candidate laboratory to the selected reference laboratory.
The candidate laboratory ( c ) shall comply with the specifications of Annex 6 of UNECE Regulation No 117 and its subsequent amendments and preferably have standard deviations ( σ m ) as follows:
(i) not greater than 0,075 kg/t for C1 and C2 tyres; and
(ii) not greater than 0,06 kg/t for C3 tyres.
If the standard deviations (σ m ) of the candidate laboratory are higher than the above values with three measurements, then the number of measurement repetitions shall be increased as follows:
n = ( σ m / γ ) 2 , rounded up to the nearest higher integer value
where:
γ 0,043 kg/t for Class C1 and C2 tyres
γ 0,035 kg/t for Class C3 tyres

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Source: https://www.legislation.gov.uk/eur/2009/1222/annex/IVa/division/5 (the official version)
Page: https://openlegislation.uk/eu-regulation-2009-1222/annex-IVa/division-5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.