State of California
AIR RESOURCES BOARD
CALIFORNIA SMOKE TEST PROCEDURES FOR NEW 1996-1999 AND LATER
HEAVY-DUTY OFF-ROAD DIESEL CYCLE ENGINES
PART III
Adopted: May 12, 1993
Amended: (date of amendment)
NOTE: The general provisions herein have been adapted and modified from similar provisions set forth in 40 CFR, Part 86, Subpart I Emission Regulations for New Diesel-Fueled Heavy-Duty Engines; Smoke Exhaust Test Procedure.
This document is printed in a style to indicate changes from the existing provisions. All existing language is indicated by plain type. All additions to language are indicated by underline. All deletions to language are indicated by strikeout.
If there is any conflict between the provisions of this document and the California Health and Safety Code, Division 26, or Title 13 of the California Code of Regulations, the Health and Safety Code and Title 13 apply.
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TABLE OF CONTENTS
Section Page
California Smoke Test Procedures For New 1996-1999 and Later Heavy-Duty Off-Road Diesel Cycle Engines 3
1. General applicability 3
2. Definitions. 3
3. Abbreviations. 3
4. [Reserved]. 3
5. Test procedures. 3
6. Fuel Specifications. 4
7. Dynamometer operation cycle for smoke emission tests 4
8. Dynamometer and engine equipment 5
9. Smoke measurement system. 6
10. Information. 9
11. Instrument Checks. 10
12. Test Run. 11
13. Data analysis. 12
14. Calculations 14
California Smoke Test Procedures For New 1996-1999 and Later HeavyDuty OffRoad Diesel Cycle Engines
1. General applicability.
These procedures are applicable to new heavy-duty off-road diesel-fueled and alternate-fueled diesel cycle engines beginning with the 1996 model year through the 1999 model year.
2. Definitions.
The definitions in the California Exhaust Emission Standards and Test Procedures for New 1996 and Later Heavy-Duty Off-Road Diesel Cycle Engines 1996-1999 Heavy-Duty Test Procedures apply.
3. Abbreviations.
The abbreviations in the California Exhaust Emission Standards and Test Procedures for New 1996 and Later Heavy-Duty Off-Road Diesel Cycle Engines 1996-1999 Heavy-Duty Test Procedures apply.
4. [Reserved].
5. Test procedures.
The procedures described in this and subsequent sections shall be the test program to determine the conformity of engines with the standards set forth in Section 11(b).
(a) The test consists of a prescribed sequence of engine operating conditions on an engine dynamometer with continuous examination of the exhaust gases. The test is applicable equally to controlled engines equipped with means for preventing, controlling, or eliminating smoke emissions and to uncontrolled engines.
(b) The test is designed to determine the opacity of smoke in exhaust emissions during those engine operating conditions which tend to promote smoke.
(c) The test procedure begins with a preconditioned engine which is then run through preloading and preconditioning operations. After an idling period, the engine is operated through acceleration and lugging modes during which smoke emission measurements are made to compare with the standards. The engine is then returned to the idle condition and the acceleration and lugging modes are repeated. Three consecutive sequences of acceleration and lugging constitutes the full set of operating conditions for smoke emission measurement.
(d) (1) Except in cases of component malfunction or failure, all emission control systems installed on, or incorporated in, a new engine shall be functioning during all procedures in this subpart.
(2) Maintenance to correct component malfunction or failure shall be authorized in accordance with Section 12 of Part I of the California Exhaust Emission Standards and Test Procedures for New 1996 and Later Heavy-Duty Off-Road Diesel Cycle Engines the 1996-1999 Heavy-Duty Test Procedures.
6. Fuel Specifications.
The fuel specifications in the California Exhaust Emission Standards and Test Procedures for New 1996 and Later Heavy-Duty Off-Road Diesel Cycle Engines 1996-1999 Heavy-Duty Test Procedures apply.
7. Dynamometer operation cycle for smoke emission tests.
(a) The following sequence of operations shall be performed during engine dynamometer testing of smoke emissions, starting with the dynamometer preloading determined and the engine preconditioned (Section 12(c)).
(1) Idle Mode. The engine is caused to idle for 5.0 to 5.5 minutes at the manufacturer's recommended curb idle speed. The dynamometer controls shall be set to provide the speed and load necessary to comply with the heavy-duty "curb idle" definition given in the California Exhaust Emission Standards and Test Procedures for New 1996 and Later Heavy-Duty Off-Road Diesel Cycle Engines, in accordance with predominant engine application.
(2) Acceleration mode.
(i) The throttle shall be moved to cause the engine speed to increase to 200 50 rpm above the measured free idle speed of the engine. The throttle shall then be moved rapidly to and held in the fully open position. The modal time duration between the point where the engine speed first begins to increase above idle speed to the point where the throttle reaches the fully open position shall be three (3) seconds, or less. The engine speed at any point during this mode shall not exceed 250 rpm above the measured free idle speed of the engine.
(ii) Upon completion of the previous mode, the inertia of the engine and the dynamometer, or a preselected dynamometer load, shall be used to control the acceleration of the engine so that the engine speed increases to 85 percent of the rated engine speed in 5 1.5 seconds. This acceleration shall be linear within 100 rpm as specified in Section 13(c).
(iii) After the engine reaches the speed required in paragraph (a)(2)(ii) of this section the throttle shall be moved rapidly to, and held in, the fully closed position. Immediately after the throttle is closed, the preselected load required to perform the acceleration in paragraph (a)(2)(iv) of this section shall be applied. For electric motoring dynamometer operation in speed mode, the deceleration shall be performed in 2 1.5 seconds.
(iv) When the engine decelerates to the intermediate speed (within 50 rpm), the throttle shall be moved rapidly to, and held in, the fully open position. The preselected dynamometer load which was applied during the preceding transition period shall be used to control the acceleration of the engine so that the speed increases to at least 95 percent of the rated speed in 10 2 seconds.
(v) For electric dynamometer operation in speed mode, motoring assist may be used to offset excessive dynamometer inertia load when necessary. No negative flywheel torque shall occur during any of the three acceleration modes in paragraph (a)(2) of this section except for a maximum of 10 footpounds for the first 0.5 second of the mode.
(3) Lugging mode.
(i) Immediately upon the completion of the preceding acceleration mode, the dynamometer controls shall be adjusted to permit the engine to develop maximum horsepower at rated speed. This transition period shall be 50 to 60 seconds in duration. During the last 10 seconds of this period, the engine speed shall be maintained within 50 rpm of the rated speed, and the power (corrected, if necessary, to rating conditions) shall be no less than 95 percent of the maximum horsepower developed during the preconditioning prior to the smoke cycle.
(ii) With the throttle remaining in the fully open position, the dynamometer controls shall be adjusted gradually so that the engine speed is reduced to the intermediate speed. This lugging operation shall be performed smoothly over a period of 35 5 seconds. The rate of slowing of the engine shall be linear, within 100 rpm, as specified in Section 13(c).
(4) Engine unloading. Within 5 seconds of completing the preceding lugging mode, the dynamometer and engine controls shall be returned to the idle position described in paragraph 7 (a)(1). The engine must be at the curb idle condition within one minute after completion of the lugging mode.
(b) The procedures described in paragraphs (a)(1) through (a)(4) of this section shall be repeated until three consecutive valid cycles have been completed. If three valid cycles have not been completed after a total of six consecutive cycles have been run, the engine shall be preconditioned by operation at a maximum horsepower at rated speed for 10 minutes before the test sequence is repeated.
8. Dynamometer and engine equipment.
The following equipment shall be used for smoke emission testing of engines on engine dynamometers:
(a) An engine dynamometer with adequate characteristics to perform the test cycle described in Section 7.
(b) An engine cooling system having sufficient capacity to maintain the engine at normal operating temperatures during conduct of the prescribed engine tests.
(c) An exhaust system where the smoke meter can be placed 15 5 feet from the engine exhaust outlet according to paragraph 9 (c). The smoke exhaust system shall present an exhaust backpressure within 0.2 inches of Hg of the upper limit at maximum rated horsepower, as established by the engine manufacturer in his sales and service literature for vehicle application.
(1) When utilizing an end-of-line smoke meter, the terminal two feet of the exhaust pipe used for smoke measurement shall be of circular cross section and be free of elbows and bends. The exit plane of the pipe where the smoke meter is mounted shall be perpendicular to the exhaust flow. The terminal two feet of the exhaust pipe shall have a nominal inside diameter in accordance with the rated power of the engine, as specified in Table 1.
TABLE 1
MaximumRated Horsepower / Exhaust Pipe DiameterStandard Optical Path Length
Less than 101 / 2 in 0.0508 m
101 to 200 / 3 in. 0.0762 m
201 to 300 / 4 in 0.1016 m
301 to 500 / 5 in. 0.1270 m
501 or more / 6 in. 0.1524 m
(2) When utilizing an inline smoke meter, there shall be no change in the exhaust pipe diameter within 3 exhaust pipe diameters before or after the smoke meter. Within 6 exhaust pipe diameters upstream of the smoke meter, no change in exhaust pipe diameter may exceed a 12 halfangle.
(d) An engine air inlet system presenting an air inlet restriction within one inch of water of the upper limit for the engine operating condition which results in maximum air flow, as established by the engine manufacturer in his sales and service literature, for the engine being tested.
9. Smoke measurement system.
(a) Schematic drawing. The figure 1841 is a schematic drawing of the optical system of the light extinction meter.
(b) Equipment. The following equipment shall be used in the system.
(1) Adapter The optical unit of end-of-line smoke meters may be mounted on a fixed or movable frame. The normal unrestricted shape of the exhaust plume shall not be modified by the adaptor, the meter, or any ventilatory system used to remove the exhaust from the test site.
(2) Smoke meter (light extinction meter) The smoke meter used must be of the fullflow light obscuration type with continuous measurement and recording capability.
(i) It is positioned in such a manner that the smoke meter light beam traverses the exhaust smoke plume at right angles to the axis of the exhaust flow.
(ii) The smoke meter light source shall be an incandescent lamp with a color temperature in the range of 2800 to 3250 K, or a green light emitting diode (LED) with a spectral peak between 550 570 nanometers.
(iii) The light output is collimated to a beam with a minimum diameter of 0.5 inches and a maximum diameter of 1.13 inches. The angle of divergence shall be within a 4 included angle.
(iv) The light detector shall be a photocell or a photodiode. If the light source is an incandescent lamp, the detector shall have a spectral response similar to the photopic curve of the human eye (a maximum response in the range of 550 to 570 nanometers, to less than 4 percent of that maximum response below 430 nanometers and above 680 nanometers).
(v) A collimating tube with apertures equal to the beam diameter is attached to the detector to restrict the viewing angle of the detector to within a 16 included angle.
(vi) An amplified signal corresponding to the amount of light blocked is recorded continuously on a remote recorder.
(vii) An air curtain across the light source and detector window assemblies may be used to minimize deposition of smoke particles on those surfaces provided that it does not measurably affect the opacity of the plume.
(viii) The smoke meter consists of two units: an optical unit and a remote control unit.
(ix) Light extinction meters employing substantially identical measurement principles and producing substantially equivalent results, but which employ other electronic and optical techniques, may be used only after having been approved in advance by the Executive Officer.
(3) Recorder a continuous recorder, with variable chart speed over a minimal range of 0.5 to 8.0 inches per minute (or equivalent) and an automatic marker indicating 1second intervals continuously records the exhaust gas opacity, engine rpm and throttle position.
(i) The recorder is equipped to indicate only when the throttle is in the fully open or fully closed position.
(ii) The recorder scale for opacity is linear and calibrated to read from 0 to 100 percent opacity full scale.
(iii) The opacity trace has a resolution within one percent opacity.
(iv) The recorder scale for engine rpm is linear and has a resolution of 30 rpm.
(v) The throttle position trace clearly indicates when the throttle is in the fully open and fully closed positions.
(vi) Any means other than a stripchart recorder may be used provided it produces a permanent visual data record of quality equal to or better than that described above (e.g., tabulated data, traces, or plots).
(4) The recorder used with the smoke meter shall be capable of fullscale deflection in 0.5 second or less. The smoke meterrecorder combination may be damped so that signals with a frequency higher than 10 cycles per second are attenuated. A separate lowpass electronic filter with the following performance characteristics may be installed between the smoke meter and the recorder to achieve the highfrequency attenuation:
(i) Three decibel point 10 cycles per second.
(ii) Insertion loss zero 0.5 decibel.
(iii) Selectivity 12 decibels per octave above 10 cycles per second.
(iv) Attenuation 27 decibels down at 40 cycles per second minimum.