Commentaries: Art. 15

The measured values shall be corrected to the reference values specified in Annex 1 Number 23.
Unless otherwise specified in Annexes 1–4, the values calculated in accordance with paragraph 1 are to be expressed as hourly mean values for the assessment. In justified cases, the authorities may specify other suitable averaging periods.
In the case of approval and control measurements, emission control requirements shall be regarded as having been complied with if none of the mean values determined in accordance with paragraph 2 exceeds the limit value.
In the case of continuous measurements, emission limit values shall be regarded as having been complied with if, within a calendar year:
1. none of the daily mean values exceeds the emission limit value;
2. 97 % of all the hourly mean values are no more than 1.2 times the limit value; and
3. none of the hourly mean values is more than twice the limit value.
The authorities shall take account of the particular circumstances when assessing emissions during start-up and shut-down periods.