vision microsystems VM1000 - 2.2 TACHOMETER OPERATION

28 SECTION
2
OPERATION
2.2
TACHOMETER
OPERATION
The
tachometer
system
provides both
a
full
sweep
graphic
analog
display
and four
place
digital
display.
When
you
start
the
engine
you
will see
the
analog
graph
rise
in
proportion to the
engine
speed.
Full
color range
marks
provide
you
with
a
quick
reference
to monitor
normal,
caution
and
red
line
engine
RPM-
RpM:
The
digital
readout
provides
you
with
exact
RPM
information.
The
resolution
(or
incremental
steps)
of
the
digital
display
is 10 RPM-
For example,
the
display
might
read
'240A'
and
after
you
make
a
slight
increase
in
power,
it would
read
'2410'.
This
is
a
definite
advantage
over
other
digital
tachs
that
read
in
less
than
10 RPM
steps.
They
change
so
frequently
that
it
becomes
very
distracting
and
annoying
to
the
pilot.
ENGINE
HOURS:
Another
feature
is
the
'engine
hours
counter'-
When
the
engine
is
off,
the
digital
display
reads
the
total
accumulated
engine
hours
to
a
maximum
of
'5999.9'. Engine
hours
are
accumulated
any
time
RPM
is
greater
than
1500
RpM
CHECKS:
The
graphic
arc
pr:ovides
40
RPM
resolution
at
engine
speeds
of
less
than
2000
RPM
(where
most
RPM
checks
are
made)
and
100
RPM
resolution
at
engine
speeds
of
2000
RPM
or
more.
you
can
of
course
use
the
digital
display
for these
checks
also.
Allow
the engine
time
to stabilize
when
performing
RPM
checks-
We
recommend
letting
the
engine
stabilize
for
a
minimum
of
three
seconds
on
each
of
these
checks
before.
noting
the
RPM
change.
The
high
accuracy
of
the
tach
will
allow
you
to
follow
long-term
performance
trends
of
your
engine
and
prop,
such
as
static
maximum
rpm,
carb
heat
effectiveness,
and
typical
mag
drops.
These
can
be
important
indicators
of engine
and
accessory
condition.
Additionally,
a
warning
alert
activates
whenever
the
engines
redline
is
reached.
The
RPM
display
will
flash
until
this
condition
is rectified.
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REv
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VMI(IIX}
OWNERS
MANUAL