StacksVerified U.S. regulatory reference

40 CFR §1065.284

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (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.
  2. (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.