Pennsylvania Code › Title 67 - TRANSPORTATION › Part I - Department of Transportation › Subpart A - Vehicle Code Provisions › Article VII - Vehicle Characteristics › Chapter 169 - DIESEL SMOKE MEASUREMENT PROCEDURE › Section 169.4 - Smoke emission test

Current through Register Vol. 54, No. 28, July 13, 2024
The following sequence of operations shall be performed
						during engine dynamometer testing for smoke emissions:
(1) Control the temperature of the air
					 supplied to the engine to between 80° and 90°F (27° and 32°C).
					 Test only when the observed barometric pressure is between 28.5 and 30.5 inches
					 (724 and 725 millimeters) of mercury in the test area. Starting with an engine
					 at operating temperature, operate the engine at the condition of maximum mass
					 fuel flow, adjust the intake air restriction to within 1 inch (25.4
					 millimeters) of water of the maximum recommended by the manufacturer and adjust
					 the exhaust system back pressure to within .2 inch (5.1 millimeters) of mercury
					 of the maximum recommended by the manufacturer. Measure and record maximum
					 observed power, fuel rate, engine speed, intake air temperature, intake air
					 restriction and exhaust back pressure.
(2) Operate the engine at the intermediate
					 speed. Measure and record maximum observed torque, fuel rate, engine speed,
					 intake air temperature, intake air restriction and exhaust back pressure.
					 Determine by experiment, if not previously determined, the preset loads
					 required by the provisions of §
											169.5 (relating to smoke test
					 cycle).
(3) Switch on the smoke
					 opacimeter. Allow for the meter circuit to stabilize according to the
					 instruction of the manufacturer. Check the linearity of the meter according to
					 the provisions of §
											169.8(a)(1) and
					 (3) (relating to instrument checks). Mount
					 the smoke opacimeter in accordance with the provisions of §
											169.7(b) 
					 (relating to equipment and instrumentation) so that the natural flow of the
					 exhaust stream is not disturbed by the meter, the mounting fixture or a
					 ventilation system.
(4) Pass the
					 exhaust flow through the smoke opacimeter so that the opacity of the exhaust
					 plume may be measured.
(5) Operate
					 the engine at maximum power for 10 minutes or until the engine coolant, oil
					 pressures and temperatures are stabilized.
(6) Discontinue passing the exhaust gas
					 stream through the meter. Set the zero and span of the smoke opacimeter
					 recorder.
(7) Operate the engine in
					 the manner required by the provisions of §
											169.5. Continuously record smoke
					 opacity and engine speed on a strip chart recorder or other appropriate
					 instrument. The chart speed shall be at least 1 inch (25 millimeters) per
					 minute during the idle mode and at least 15 inches (381 millimeters) per minute
					 during acceleration and lugging modes.
(8) Repeat the procedures as contained in the
					 provisions of §
											169.5(a)-(d)
					 until the entire cycle has been run three consecutive times. If the
					 acceleration and lugging modes have been performed within the tolerances
					 specified in the provisions of §
											169.5, then the tests may be
					 terminated at this time. If not, then the test procedure shall be rerun until
					 data have been obtained within the specified limits.
(9) Within 1 minute after completion of the
					 requirements of paragraph (8), recheck the calibration of the smoke opacimeter
					 as described in paragraph (6). If either zero or span drift is in excess of 2%
					 opacity, the test results should be considered invalid.
This section cited in 67 Pa. Code §
													169.5 (relating to smoke test
						  cycle); and 67 Pa. Code §
													169.7 (relating to equipment and
						  instrumentation).