Table of Contents
Advertisement
db
0
20
O~b
I
[
I
~Accelerometer
(1000pF)
,~~
/ /
~
~~
~Accelerometer (400 pF)
I
I
~38d~
i
I
1
5
10
2
- - - - .
Frequency
J
db tl
+20~b
-
~
+38 db
" ·
'
10
4
2
C/5
5
10
5
.?61193
Fig.
10.
Typical amplitude versus frequency response of the combinations
illustrated in Fig.
9.
At the low frequencies tl1e curves are valid for the
complete set-up including Accelerometer, Preamplifier and Indicator. At the
high frequencies the
curves
illustrate the response without Accelerometer,
i.e.
for the Preamplifier plus indicator only.
The indication "0
dB",
"+
30
dB"
and
"0
dB
to
+
20
dB"
on
th
e
curves
refer
to the position of
"Sensitivity
Adjustment" when the amplifier stage gives the
amplifications stated thereby.
quencies of the measuring set-up employing various lengths of Extension
Cables can be seen from the dotted curves in Fig. 2b.
NOTE: The measuring cable connecting the Accelerometer to the
Pre-
amplifier should, if possible, not be extended.
Calibration of the Measuring System.
To calibrate the measuring arrangement the built-in shaker table can be
used. When the set-up is connected as described under
"Measuring
Arrange-
ment", the Accelerometer could be screwed onto the table by a
lfs"
Whit-
worth screw.
NOTE: The Accelerometer can also be mounted by other means as explained
in
the manua
l for
the
Accelerometers.
Thereafter the measuring cable from Accelerometer to Preamplifier is
screwed
on the Accelerometer and connected to the "Input" of the Pre-
amplifier. By following this sequence twisting of the cable is avoided.
1. Connect the Preamplifier to the mains.
NOTE: The Preamplifier (shaker table) can be driven from mains volt-
ages between 100 V
and
240 V (50 or 60Hz
(c/s))
without
any
adjustment.
2. Set the control knobs of the Preamplifier as follows:
12
"Attenuation" on "1"
"Sensitivity Adjustment" on "0", and
Integration Switch on
"Acceleration".
Advertisement
Table of Contents
