Mininoise coaxial accelerometer cable
is
available in
any
length
up
to
200m
(600ft)
from
Bruel &
Kj<Er.
There
are
two
types,
Type
AC
0010
(PVC insulated)
for
ordinary
temperatures,
and
Type
AC
0005
(Teflon)
for
a wide
temperature
range
(-90
to+
250°C).
The
appropriate
microplugs are
also available,
with
tools
and instructions
for
mounting
in
the
kit UA
0129.
See Accessories.
3.2. OUTPUT
If
the
output
is
taken
via a miniature cable, an
adapter
may
be necessary
to
feed
the
output
signal
to
the
next
instrument.
An
alternative BNC
output
socket
is
available
for
connection
to
the
input
of
the
analyzing and
indicating
instrumentation.
In
the
DIRECT
output
mode,
the
signal could
be off-set
by
max.±
10
mV. When
the
preamplifier
is
used in a servo-loop in
exciter systems,
the
TRANSFORMER
output
mode
may advantageously be
used since
the
output
is
floating. Problems arising
from
ground loops can
thus
be
avoided. Care should, however, be
taken
with this
output
below
40Hz
and
above
10kHz.
Below
40Hz
the
available
output
amplitude
is
limited
by
saturation
of
the
transformer
iron
at
a rate of 6 dB/octave.
Above
10kHz
large capacitive loads
may
introduce
peaking effects.
3.3. POWER REQUIREMENTS
The
preamplifier can be
operated
from
any
line voltage
between
90
and
265
Volts AC,
without
adjustments
required
for
the
instrument. Maximum
power
consumption
is
approximately
7 Watts.
3.4.
OVERLOAD RESET
The
use
of
this
button
restores immediately normal
operating
conditions
after overload when
the
preamplifier
is
used
in
low
frequency
modes
for
impulse (shock) measurements.
3.5. USE IN SERVO
LOOPS
OF EXCITER CONTROL SYSTEMS
On
account
of
quick
recovery
time
the
preamplifier can be used in servo
loops in exciter systems.
It should
be
noted,
however,
that
it
is
dangerous
to
unplug loads
or
alter switch positions during a vibration test, as sudden
changes
in
levels could
occur
at
the
exciter
table
resulting in damage
to
the
specimen
or
the
table itself.
14
To Next Page
Loading...
