Textual Amendments
F1 Inserted by Commission Regulation (EU) No 1235/2011 of 29 November 2011 amending Regulation (EC) No 1222/2009 of the European Parliament and of the Council with regard to the wet grip grading of tyres, the measurement of rolling resistance and the verification procedure (Text with EEA relevance).
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:
not greater than 0,075 kg/t for C1 and C2 tyres; and
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:
=
0,043 kg/t for Class C1 and C2 tyres
=
0,035 kg/t for Class C3 tyres]