CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 86—CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES > SUBPART D—Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test Procedures (§86.301-79 to §86.348-79) > 86.316-79—Carbon monoxide and carbon dioxide analyzer specifications.

86.316-79—Carbon monoxide and carbon dioxide analyzer specifications.

(a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers.
(b) The use of linearizing circuits is permitted.
(c) The minimum water rejection ratio (maximum CO 2 interference) as measured by § 86.321 shall be:
(1) For CO analyzers, 1000:1.
(2) For CO 2 analyzers, 100:1.
(d) The minimum CO 2 rejection ratio (maximum CO 2 interference) as measured by § 86.322 for CO analyzers shall be 5000:1.
(e) Zero suppression. Various techniques of zero suppression may be used to increase readability, but only with prior approval by the Administrator.