ENGINE DIAGNOSTIC TEST PROCEDURES
MEASURE SMOKE INTENSITY (Continued)
NOTE: To make sure that there are no soot particles
of previous tests in the sampling probe or hose
which might influence the measuring results, hose
and sampling probe have to be blown out with
compressed air before the test. A check should be
made by pumping fresh air through a filter disk. The
disk must not darken.
Install the sampling probe as follows:
When used with an open exhaust stack, the
probe must be used with the standard probe
shield and inserted axially into the end of the
pipe, keeping away from the wall. Normally, it
will be convenient to use the furnished clamp to
position and fasten probe in stack.
For closed stack installations, the standard
probe with the tip shield removed can be
inserted through a snug fitting hole in the side
of the stack. Care must be taken to keep the
probe at 90° with the flow, to eliminate velocity
If samples are taken from the exhaust systems
operating at pressure over 2.5 kPa (10 inches H20)
from barometeric pressure, then correction must be
made for density of the sample. A typical correction
chart is furnished with the smoke meter.
Insert sampling probe (1, Figure 30) into exhaust
pipe. When possible, avoid locating near a bend.
Cock the pump (3, Figure 30) by pushing plunger
knob (5) all the way in until latch holds spring
Unscrew cap nut (2, Figure 30) to allow insertion of
clean filter disc and clamp filter by moderate
tightening of cap nut.
Release suction stroke by squeezing rubber bulb (4,
Loosen cap nut and remove filter discs.
Repeat Steps 4, 5, 6 and 7 until three uniformly
darkened discs are obtained.
Compare sample discs with "Bacharach Oil Burner
Smoke Scale," represented in Chart C.
DO NOT COMPARE SAMPLE DISCS WITH
SMOKE SCALE REPRESENTED IN CHART C.
Order Bacharach Oil Burner Smoke Scale from:
A. A. Englehardt Company
6117 North Elston Avenue
Chicago, I L. 60646
Figure 30. Obtaining Smoke Sample with
Printed in United States of America