[Code of Federal Regulations]
[Title 40, Volume 30]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1065.615]

[Page 672-673]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 1065_TEST PROCEDURES AND EQUIPMENT--Table of Contents
 
                Subpart G_Data Analysis and Calculations
 
Sec. 1065.615  Bag sample calculations.

    (a) Calculate the dilution factor. The dilution factor is the ratio 
of the total volume of the raw exhaust to the total volume of the 
diluted exhaust. It is calculated as 134,000 divided by the sum of the 
diluted ppmC concentrations of carbon-containing compounds in the 
exhaust, as follows:

DF = 134,000/
    (CO2sample+THCsample+COsample),

Where:

CO2sample and COsample are expressed as ppm, and 
THCsample is expressed as ppmC.

    (b) Calculate mass emission rates (g/test) for the transient segment 
using the general equation in paragraph (b)(1) of this section:
    (1) The general equation is:

Emission rate = (total dilute exhaust flow volume)(ppm)(density factor)/
    10\6\

Mx = (Vmix)(Ci)(fdi)/10\6\

Where:

Mx = Mass emission rate in g/test segment.

[[Page 673]]

Vmix = Total dilute exhaust flow volume flow in m\3\ per test 
segment corrected to 20[deg]C and 101.3 kPa.
Ci = The concentration of species i, in ppm or ppmC, 
corrected for background contribution according to the equation in 
paragraph (b)(2) of this section.
fdi = The density factor for species i. The density factors 
are 576.8 g/m\3\ for THC, 1913 g/m\3\ for NOX, and 1164 g/
m\3\ for CO.

    (2) The equation to calculate Ci is:

Ci = Csample-Cbackground [1--(1/DF)]

Where:

Csample = Concentration of species i in the diluted exhaust 
sample, in ppm or ppmC.
Cbackground = Concentration of species i in the dilution air 
background sample, in ppm or ppmC.
DF = Dilution factor, as calculated in paragraph (a) of this section.

    (c) Calculate total brake work (kW-hr) done during the emissions 
sampling period of each segment or mode.
    (d) Calculate emissions in g/kW-hr by dividing the mass emission 
rate (g/test segment) by the total brake work for the test segment.
    (e) Apply deterioration factors or other adjustment factors to the 
brake-specific emission rate in paragraph (e) as specified in the 
standard-setting part.

    Effective Date Note: At 69 FR 39262, June 29, 2004, Sec. 1065.615 
was amended by revising paragraphs (c), (d) and (e), effective Aug. 30, 
2004. For the convenience of the user, the revised text is set forth as 
follows:

Sec. 1065.615  Bag sample calculations.

                                * * * * *

    (c) Calculate total brake work (kW-hr) done during the emissions 
sampling period of each segment or mode and then weight it by the 
applicable test cycle weighting factors.
    (d) Calculate emissions in g/kW-hr by dividing the total weighted 
mass emission rate (g/test) by the total cycle-weighted brake work for 
the test.
    (e) Apply deterioration factors or other adjustment factors to the 
brake-specific emission rate in paragraph (d) of this section, as 
specified in the standard-setting part.