40 CFR § 1065.250 - Nondispersive infrared analyzer.

---
identifier: "/us/cfr/t40/s1065.250"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 1065.250 - Nondispersive infrared analyzer."
title_number: 40
title_name: "Protection of Environment"
section_number: "1065.250"
section_name: "Nondispersive infrared analyzer."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "U"
subchapter_name: "AIR POLLUTION CONTROLS"
part_number: "1065"
part_name: "ENGINE-TESTING PROCEDURES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401-7671q."
regulatory_source: "70 FR 40516, July 13, 2005, unless otherwise noted."
cfr_part: "1065"
---


# 1065.250 Nondispersive infrared analyzer.

(a) *Application.* Use a nondispersive infrared (NDIR) analyzer to measure CO and CO<sub>2</sub> concentrations in raw or diluted exhaust for either batch or continuous sampling.

(b) *Component requirements.* We recommend that you use an NDIR analyzer that meets the specifications in Table 1 of § 1065.205. Note that your NDIR-based system must meet the calibration and verifications in §§ 1065.350 and 1065.355 and it must also meet the linearity verification in § 1065.307.

[76 FR 57442, Sept. 15, 2011, as amended at 79 FR 23761, Apr. 28, 2014]