Division 8.2.2.2 Drift validation and drift correction

If the drift is within ±1 %, the data can be either accepted without any correction or accepted after correction. If the drift is greater than ± 1 %, two sets of brake specific emission results shall be calculated for each pollutant with a brake-specific limit value and for CO₂, or the test shall be voided. One set shall be calculated using data before drift correction and another set of data calculated after correcting all the data for drift in accordance with point 2.6 of Annex VII and Appendix 1 of Annex VII. The comparison shall be made as a percentage of the uncorrected results. The difference between the uncorrected and the corrected brake-specific emission values shall be within ± 4 % of either the uncorrected brake-specific emission values or the emission limit value, whichever is greater. If not, the entire test is void.