Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

Pollutant Concentration range, parts per million (ppm) Simultaneous measurements required Maximum discrepancy specification, parts per million 1-hour 24-hour First set Second set First set Second set Ozone Low 0.06 to 0.10 5 6 0.02 Med. 0.15 to 0.25 5 6 0.03 High 0.35 to 0.46 4 6 0.04 Total 14 18 Carbon monoxide Low 7 to 11 5 6 1.5 Med. 20 to 30 5 6 2.0 High 25 to 45 4 6 3.0 Total 14 18 Sulfur dioxide Low 0.02 to 0.05 5 6 3 3 0.02 Med. 0.10 to 0.15 5 6 2 3 0.03 High 0.30 to 0.50 4 6 2 2 0.04 Total 14 18 7 8 Nitrogen dioxide Low 0.02 to 0.08 3 3 0.02 Med. 0.10 to 0.20 2 2 0.02 High 0.25 2 2 0.03 Total 7 8 [75 FR 35601, June 22, 2010]