eCFR Reference Browser

---

title: "40 CFR §1065.660"

source: "https://www.ecfr.gov/current/title-40/section-1065.660"

title_number: "40"

volume_number: "37"

chapter_number: "Unknown"

subchapter_code: "U"

subchapter_subject: "AIR POLLUTION CONTROLS"

part_code: "1065"

part_subject: "ENGINE-TESTING PROCEDURES"

subpart_code: "G"

subpart_subject: "Calculations and Data Requirements"

section_number: "1065.660"

section_subject: "THC, NMHC, NMNEHC, CH"

cfr_reference: "40 CFR 1065.660"

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)THC determination and initial THC/CH

contamination corrections. (1) If we require you to determine THC emissions, calculate x

THC[THC-FID]cor using the initial THC contamination concentration x

THC[THC-FID]init from § 1065.520 as follows:

(2)For the NMHC determination described in paragraph (b) of this section, correct x

THC[THC-FID] for initial THC contamination using Eq. 1065.660-1. You may correct x

THC[NMC-FID] for initial contamination of the CH4 sample train using Eq. 1065.660-1, substituting in CH4 concentrations for THC.

(3)For the NMNEHC determination described in paragraph (c) of this section, correct x

THC[THC-FID] for initial THC contamination using Eq. 1065.660-1. You may correct x

THC[NMC-FID] for initial contamination of the CH4 sample train using Eq. 1065.660-1, substituting in CH4 concentrations for THC.

(4)For the CH4 determination described in paragraph (d) of this section, you may correct x

THC[NMC-FID] for initial THC contamination of the CH4 sample train using Eq. 1065.660-1, substituting in CH4 concentrations for THC.

(b)NMHC determination. Use one of the following to determine NMHC concentration, x

NMHC:

(1)If you do not measure CH4, you may omit the calculation of NMHC concentrations and calculate the mass of NMHC as described in § 1065.650(c)(5).

(2)For nonmethane cutters, calculate x

NMHC using the nonmethane cutter's penetration fraction (PF) of CH4 and the response factor penetration fraction (RFPF) of C2H6 from § 1065.365, the response factor (RF) of the THC FID to CH4 from § 1065.360, the initial THC contamination and dry-to-wet corrected THC concentration x

THC[THC-FID]cor as determined in paragraph (a) of this section, and the dry-to-wet corrected CH4 concentration x

THC[NMC-FID]cor optionally corrected for initial THC contamination as determined in paragraph (a) of this section.

(i)Use the following equation for penetration fractions determined using an NMC configuration as outlined in § 1065.365(d):

(ii)For penetration fractions determined using an NMC configuration as outlined in section § 1065.365(e), use the following equation:

(iii)For penetration fractions determined using an NMC configuration as outlined in section § 1065.365(f), use the following equation:

(3)For a GC-FID or FTIR, calculate x

NMHC using the THC analyzer's response factor (RF) for CH4, from § 1065.360, and the initial THC contamination and dry-to-wet corrected THC concentration x

THC[THC-FID]cor as determined in paragraph (a) of this section as follows:

(4)For an FTIR, calculate x

NMHC by summing the hydrocarbon species listed in § 1065.266(c) as follows:

(c)NMNEHC determination. Use one of the following methods to determine NMNEHC concentration, x

NMNEHC:

(1)If the content of your test fuel contains less than 0.010 mol/mol of ethane, you may omit the calculation of NMNEHC concentrations and calculate the mass of NMNEHC as described in § 1065.650(c)(6).

(2)For a GC-FID or FTIR, calculate x

NMNEHC using the THC analyzer's response factors (RF) for CH4 and C2H6, from § 1065.360, and the initial contamination and dry-to-wet corrected THC concentration x

THC[THC-FID]cor as determined in paragraph (a) of this section as follows:

(3)For an FTIR, calculate x

NMNEHC by summing the hydrocarbon species listed in § 1065.266(c) as follows:

(d)CH

determination. Use one of the following methods to determine CH4 concentration, x

CH4:

(1)For nonmethane cutters, calculate xCH4 using the nonmethane cutter's penetration fraction (PF) of CH4 and the response factor penetration fraction (RFPF) of C2H6 from § 1065.365, the response factor (RF) of the THC FID to CH4 from § 1065.360, the initial THC contamination and dry-to-wet corrected THC concentration x

THC[THC-FID]cor as determined in paragraph (a) of this section, and the dry-to-wet corrected CH4 concentration x

THC[NMC-FID]cor optionally corrected for initial THC contamination as determined in paragraph (a) of this section.

(i)Use the following equation for penetration fractions determined using an NMC configuration as outlined in § 1065.365(d):

(ii)For penetration fractions determined using an NMC configuration as outlined in § 1065.365(e), use the following equation:

(iii)For penetration fractions determined using an NMC configuration as outlined in § 1065.365(f), use the following equation:

(2)For a GC-FID or FTIR, x

CH4 is the actual dry-to-wet corrected CH4 concentration as measured by the analyzer.

(e)C

determination. For a GC-FID or FTIR, x

C2H6 is the C1-equivalent, dry-to-wet corrected C2H6 concentration as measured by the analyzer.

§1065.660 - THC, NMHC, NMNEHC, CH