eCFR Reference Browser

---

title: "40 CFR §89.414"

source: "https://www.ecfr.gov/current/title-40/section-89.414"

title_number: "40"

volume_number: "22"

chapter_number: "Unknown"

subchapter_code: "C"

subchapter_subject: "AIR PROGRAMS (CONTINUED)"

part_code: "89"

part_subject: "CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES"

subpart_code: "E"

subpart_subject: "Exhaust Emission Test Procedures"

section_number: "89.414"

section_subject: "Air flow measurement specifications."

cfr_reference: "40 CFR 89.414"

title_name: "Title 40"

title_subject: "Protection of Environment"

parts_covered: "Parts 87 to 95"

revised_date: "Revised as of July 1, 2017"

publication_date: "As of July 1, 2017"

contains_description: "Containing a codification of documents of general applicability and future effect"

publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"

---

(a)The air flow measurement method used must have a range large enough to accurately measure the air flow over the engine operating range during the test. Overall measurement accuracy must be ±2 percent of the maximum engine value for all modes. The Administrator must be advised of the method used prior to testing.

(b)When an engine system incorporates devices that affect the air flow measurement (such as air bleeds) that result in understated exhaust emission results, corrections to the exhaust emission results shall be made to account for such effects.

§89.414 - Air flow measurement specifications.