eCFR Reference Browser

---

title: "40 CFR §1066.610"

source: "https://www.ecfr.gov/current/title-40/section-1066.610"

title_number: "40"

volume_number: "37"

chapter_number: "Unknown"

subchapter_code: "U"

subchapter_subject: "AIR POLLUTION CONTROLS"

part_code: "1066"

part_subject: "VEHICLE-TESTING PROCEDURES"

subpart_code: "G"

subpart_subject: "Calculations"

section_number: "1066.610"

section_subject: "Dilution air background correction."

cfr_reference: "40 CFR 1066.610"

title_name: "Title 40"

title_subject: "Protection of Environment"

parts_covered: "Part 1060 to End"

revised_date: "Revised as of July 1, 2019"

publication_date: "As of July 1, 2019"

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)Correct the emissions in a gaseous sample for background using the following equation:

(c)Determine the dilution factor, DF, over the test interval for partial-flow dilution sample systems using the following equation:

dexhstd = total dilute exhaust volume sampled over the test interval, corrected to standard reference conditions.

exhstd = total exhaust volume sampled from the vehicle, corrected to standard reference conditions.

(d)Determine the time-weighted dilution factor, DF

w, over the duty cycle using the following equation:

§1066.610 - Dilution air background correction.