Sun Microsystems MCS 2000 SL - Page 65

UNDERSTANDING
FOU R
GAS
ANALYSIS
GENERAL
This
chapter
is
jntended
to
be
technica'l
information
rather than an
operation
procedure
for the MCS2000SL.
The full value
and
benefits of understanding four-gas ana'lysis
will
become
apparent as
you
use
your
"MCS2000SL"
to
obtain data
to diagnose engine
problems
and
make necessary
repairs.
IDEAL ENGINE
If
we
could'imag'ine
the
"Ideal"
internal
Combust'ion
Engine,
it would
burn
its fuel
completely.
The
combustion by-products
(the
exhaust
gas)
of this
theoretical
ideal
engine
would
be Carbon Dioxide
(CO2)
and
water vapour
(H2O).
t
Figure
33, Ideal
Engine
REAL-
WORLD
ENGINE
Unfortunately,
nothing
is
perfect.
In the real
world
engine,
the flame
front
is
set off
by the
spark and
hits
the relatively
cool
cylinder
walls. At
this
cool
cylinder wall,
not
all
fuel
will
be
burnt.
Also,
if the
carburettor or
injection
system is improperly
adjusted, the
"Air
Fuel"
ratios are incorrect
for
complete
combustion
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59
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