Section 1065.284 - Zirconium dioxide (ZrO[2]) air-fuel ratio and O[2] analyzer(a)Application. You may use a zirconia (ZrO2) analyzer to measure air-to-fuel ratio in raw exhaust for continuous sampling. You may use O2 measurements with intake air or fuel flow measurements to calculate exhaust flow rate according to § 1065.650 .(b)Component requirements. We recommend that you use a ZrO2 analyzer that meets the specifications in § 1065.205 . Note that your ZrO2-based system must meet the linearity verification in § 1065.307 . 70 FR 40516 , July 13, 2005, as amended at 76 FR 57443 , Sept. 15, 2011; 79 FR 23762 , Apr. 28, 2014; 89 FR 29797 , Apr. 22, 2024 88 FR 4673 , 3/27/2023; 89 FR 29797 , 6/21/2024