a. Follow the
manufacturer's instruction for on the proper installation,
and checking the accuracy and calibration before and after each test.
b. Set the vehicle
control in the neutral position and the hand-brake effectively engaged.
c. Start the engine
it up to its normal operating temperature.
d. Accelerate the
two to three times (2-3) prior to smoke sampling in order to remove
of soot and other carbon particles in the tail pipe.
e. With the engine
depress the accelerator quickly, but not violently, to obtain maximum
from the injection pump. Maintain this position until maximum engine
is reached for about two (2) to four (4) seconds and the governor comes
into action. As soon as this speed is reached, release the accelerator
until the engine resumes its idling speed. Record the maximum reading
f. The operation
in paragraph (4)(e) shall be repeated not less than six (6) times in
to clear the exhaust system and to allow for any necessary adjustment
the apparatus. The maximum opacity values read in each successive
shall be noted until stabilized values are obtained. The values read
be regarded as stabilized when four (4) consecutive readings are within
a hand width of 0.25 m-1 and do not form a decreasing sequence. The
mean of the four stabilized values shall be the test result for the
g. For motor vehicles
with several exhaust outlets that are individually connected from
exhaust ports, the free acceleration test shall be carried out on each
outlet. In this case, the values used for calculating the correction to
the absorption coefficient shall be arithmetical mean values recorded
each outlet and the test shall be valid only if the extreme values
do not differ by more than 0.15m-1 For motor vehicles designed with
exhaust outlets connected from one exhaust pipe coming from the
exhaust manifold collector, the free acceleration test shall be carried
out only on one exhaust outlet, the other outlets effectively blocked
h. Seal the full load
of the injection pump/delivery system of the motor vehicle after a
to prevent tampering.