Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:16:p89
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 16 (pt 89/108)
Character Range: 1139863–1142771

mass and number of all emissions, where applicable, shall be calculated according to Annex B7.
              2.14.2.10. Calibrations and checks shall be performed either:
                  (a)  Before and after each bag pair analysis; or
                  (b)  Before and after the complete test.
              In case (b), calibrations and checks shall be performed on all analysers for all ranges used during the test.
              In both cases, (a) and (b), the same analyser range shall be used for the corresponding ambient air and exhaust bags.
              2.14.3. Particulate sample filter weighing
              2.14.3.1. The particulate sample filter shall be returned to the weighing chamber (or room) no later than 1 hour after completion of the test. It shall be conditioned in a petri dish, which is protected against dust contamination and allows air exchange, for at least 1 hour, and weighed. The gross weight of the filter shall be recorded.
              2.14.3.2. At least two unused reference filters shall be weighed within 8 hours of, but preferably at the same time as, the sample filter weighings. Reference filters shall be of the same size and material as the sample filter.
              2.14.3.3. If the specific weight of any reference filter changes by more than ±5 μg between sample filter weighings, the sample filter and reference filters shall be reconditioned in the weighing chamber (or room) and reweighed.
              2.14.3.4. The comparison of reference filter weighings shall be made between the specific weights and the rolling arithmetic average of that reference filter's specific weights. The rolling arithmetic average shall be calculated from the specific weights collected in the period after the reference filters were placed in the weighing chamber (or room). The averaging period shall be at least one day but not more than 15 days.
              2.14.3.5. Multiple reconditionings and reweighings of the sample and reference filters are permitted until a period of 80 hours has elapsed following the measurement of gases from the emissions test. If, prior to or at the 80-hour point, more than half the number of reference filters meet the ±5 μg criterion, the sample filter weighing may be considered valid. If, at the 80-hour point, two reference filters are employed and one filter fails the ±5 μg criterion, the sample filter weighing may be considered valid under the condition that the sum of the absolute differences between specific and rolling means from the two reference filters shall be less than or equal to 10 μg.
              2.14.3.6. In the case that less than half of the reference filters meet the ±5 μg criterion, the sample filter shall be discarded, and the emissions test repeated. All reference filters shall be discarded and replaced within 48 hours. In all other cases, reference filters shall be replaced at least every 30