[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: 40CFR1065.530]
[Page 670-672]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 1065_TEST PROCEDURES AND EQUIPMENT--Table of Contents
Subpart F_Running an Emission Test
Sec. 1065.530 Test cycle validation criteria.
(a) Steady-state emission testing. Make sure your engine's speeds
and loads stay within 2 percent of the set point
during the sampling period.
(b) Transient emission testing performed by EPA. Emission tests must
meet the specifications of this paragraph (b). Otherwise, they do not
comply with the test cycle requirements of the standard-setting part,
unless we determine the cause of the failure to meet these
specifications is related to the engine rather than the test equipment.
(1) Shifting feedback signals. The time lag between the feedback and
reference-cycle values may bias results. To reduce this effect, you may
advance or delay the entire sequence of engine-speed and torque-feedback
signals with respect to the reference sequence for speed and torque. If
you shift the feedback signals, you must shift speed and torque the same
amount in the same direction.
(2) Calculating brake kilowatt-hour emissions. Calculate brake
kilowatt-hour emissions for each pair of feedback values recorded for
engine speed and torque. Also calculate the reference brake kilowatt-
hour for each pair of reference values for engine speed and torque.
Calculate to five significant figures.
(3) Performing regression-line analysis. Perform regression analysis
to calculate validation statistics as follows:
(i) Perform linear regressions of feedback value on reference value
for speed, torque, and brake power on 1 Hz data after the feedback shift
has occurred (see paragraph (b)(1) of this section). Use the method of
least squares, with the best-fit equation having the form:
y = mx + b
Where:
y = The feedback (actual) value of speed (rpm), torque (ft-lbs.), or
brake power.
m = Slope of the regression line.
x = The reference value (speed, torque, or brake power).
b = The y-intercept of the regression line.
(ii) Calculate the standard error of estimate (SE) of y on x and the
coefficient of determination (r\2\) for each regression line.
(iii) For a valid test, make sure the feedback cycle's integrated
brake kilowatt-hour is within 5 percent of the reference cycle's
integrated brake kilowatt-hour. Also, ensure that the slope, intercept,
standard error, and coefficient of determination meet the criteria in
the following table (you may delete individual points from the
regression analyses, consistent with good engineering judgment):
Table 1 of Sec. 1065.530--Statistical Criteria for Validating Test Cycles
----------------------------------------------------------------------------------------------------------------
Speed Torque Power
----------------------------------------------------------------------------------------------------------------
1. Slope of the regression line (m).. 0.980 to 1.020......... 0.880 to 1.030......... 0.880 to 1.030.
--------------------------------------
2. Y intercept of the regression line >< a< a<
h > >
<< << <<
h< <= 40 rpm. >< <= 5.0 percent of >< <= 3.0 percent of
maximum torque from maximum torque from
power map. power map.
--------------------------------------
3. Standard error of the estimate of 100 rpm................ 15 percent of maximum 10 percent of maximum
Y on X (SE). torque from power map. power from power map.
--------------------------------------
4. Coefficient of determination r\2\ = 0.970 r\2\ = 0.900 r\2\ =
(r\2\). 0.900.
----------------------------------------------------------------------------------------------------------------
(c) Transient testing performed by manufacturers. Emission tests
that meet the specifications of paragraph (b) of this section satisfy
the standard-setting part's requirements for test cycles. You may ask to
use a dynamometer that cannot meet those specifications, consistent with
good engineering practice. We will approve your request
[[Page 671]]
as long as using the alternate dynamometer does not affect your ability
to show that you comply with all applicable emission standards.
Effective Date Note: At 69 FR 39261, June 29, 2004, Sec. 1065.530
is amended by revising paragraph (b)(3)(iii) and adding paragraphs (d)
and (e), effective Aug. 30, 2004. For the convenience of the user, the
revised text is set forth as follows:
Sec. 1065.530 Test cycle validation criteria.
* * * * *
(b) * * *
(3) * * *
(iii) For a valid test, make sure the feedback cycle's integrated
brake kilowatt-hour is within 5 percent of the reference cycle's
integrated brake kilowatt-hour. Also, ensure that the slope, intercept,
standard error, and coefficient of determination meet the criteria in
the following tables (you may delete individual points from the
regression analyses, consistent with paragraph (e) of this section and
good engineering judgment):
Table 1 of Sec. 1065.530.--Statistical Criteria for Validating Test Cycles for Spark-Ignition Engines
----------------------------------------------------------------------------------------------------------------
Speed Torque Power
----------------------------------------------------------------------------------------------------------------
1. Slope of the regression line (m).. 0.950 to 1.030......... 0.830 to 1.030......... 0.880 to 1.030.
2. Y intercept of the regression line [verbar]b[verbar] <= 50 [verbar]b[verbar] <= [verbar]b[verbar] <=
(b). rpm. 5.0 percent of maximum 3.0 percent of maximum
torque from power map. torque from power map.
3. Standard error of the estimate of 100 rpm................ 15 percent of maximum 10 percent of maximum
Y on X (SE). torque from power map. power from power map.
4. Coefficient of determination (r r \2\ = r \2\ = r \2\ =
\2\). 0.970. 0.880. 0.900.
----------------------------------------------------------------------------------------------------------------
Table 2 of Sec. 1065.530.--Statistical Criteria for Validating Test Cycles for Compression-Ignition Engines
----------------------------------------------------------------------------------------------------------------
Speed Torque Power
----------------------------------------------------------------------------------------------------------------
1. Slope of the regression line (m).. 0.950 to 1.030......... 0.830 to 1.030 (hot); 0.890 to 1.030 (hot);
0.77 to 1.03 (cold). 0.870 to 1.030 (cold).
2. Y intercept of the regression line [verbar]b[verbar] <= 50 [verbar]b[verbar] <= 20 [verbar]b[verbar] <=
(b). rpm. Nm or 4.0 kW or
[verbar]b[verbar] <= [verbar]b[verbar] <=
2.0 percent of maximum 3.0 percent of maximum
torque from power map, torque from power map,
whichever is greater. whichever is greater.
3. Standard error of the estimate of 100 rpm................ 13 percent of maximum 8 percent of maximum
Y on X (SE). torque from power map. power from power map.
4. Coefficient of determination (r r \2\ = r \2\ = r \2\ =
\2\). 0.970. 0.880 (hot); r \2\ = 0.850 (cold);. thn-eq>= 0.850 (cold).
----------------------------------------------------------------------------------------------------------------
* * * * *
(d) Transient testing with constant-speed engines. For constant-
speed engines with installed governor operating over a transient duty
cycle, the test cycle validation criteria in this section apply to
engine-torque values but not engine-speed values.
(e) Omissions. You may omit the following points from duty cycle
statistics calculations:
(1) Feedback torque and power during motoring reference commands
when operator demand is at its minimum.
(2) Feedback speed and power during idle-speed oscillations, if all
the following are true:
(i) Reference command is 0% speed and 0% torque.
(ii) Operator demand (i.e., throttle) is at its minimum.
(iii) Absolute value of feedback torque is less than the sum of the
reference torque plus 2% of the maximum mapped torque.
(3) Feedback power and either speed or torque for a given point when
approaching maximum demand, if all the following are true:
(i) Operator demand (i.e., throttle) is at its maximum.
(ii) Either feedback speed is less than reference speed or feedback
torque is less than reference torque, but both are not less than their
respective reference values.
(4) Feedback power and either speed or torque for a given point,
when approaching minimum demand, if all the following are true:
(i) Operator demand (i.e., throttle) is at its minimum.
(ii) Either feedback speed is greater than 105% of reference speed
or feedback torque is
[[Page 672]]
greater than 105% of reference torque, but both are not greater than
these values.