---
kind: "section"
citation: "40 C.F.R. § 1065.284"
title: "40"
number: "1065.284"
heading: "Zirconium dioxide (ZrO 2 ) air-fuel ratio and O 2 analyzer."
url: "https://uscodex.org/cfr/40/1065.284"
---

# §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](/cfr/40/1065.650.md).
- (b) **Component requirements.** We recommend that you use a ZrO2 analyzer that meets the specifications in [§ 1065.205](/cfr/40/1065.205.md). Note that your ZrO2-based system must meet the linearity verification in [§ 1065.307](/cfr/40/1065.307.md).

## Notes

### Amendments

[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]

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Source

Source: 70 FR 40516, July 13, 2005, unless otherwise noted.

### Amendments

[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]