Table of Contents
Advertisement
3. Set
"Acceleration
Range" to
th
e
desired acceleration range using the
proper part of the switch
("Accel.
Gen." or
"Vel.
Gen.")
.
Note: The figures
"1", "10",
"100"
,
and
"1ooo"
indicate full-scale meter
deflection peak value acceleration levels in multiples of G.
4. Turn the
"Output
Voltage"
knob
slowly
clockwise until the
compressor
has taken over the
control
of the output voltage.
(This can
be observed
on the instrument meter, the pointer of which should be kept below the
5 db mark on the scale).
5.
Turn the knob marked
"Acceleration
Level"
clockwise until the instru-
ment meter pointer indicates the desired vibration level.
f).
Follow instructions item 16 through 18 under
"
Operation
at Constant
Displacement Level".
(Page
18)
.
Lo
1
;;
20
ld
f.-
(j_
I
II
I
1
/
1
11
;
Ill
1
/
;
1
//
lj
lj
1"1
1
/
j
II;
'
j ll
j
I
t I
1/j
1//
7
17;
I
I
/VI
Il
l
r
;
/
llj
Ill
l/'~~;,:;r77
7
171
~r~~~
)
II
lj
I
I /
'
j
l
i
%_~§1;,
1//
Jll
1
lli
VI,
1/
j
II
IV
1//.
'/lJ
r11
j
l
v
lj
500 HXXl2000
5000
Frequtncy in cpL
a
.
Fft~ency incps
b.
c.
R"equtncyincps
26DIN
Fig. 8. Diagrams showing the possible cross-over points as a function of
frequency.
All
values within the thick lines can be used.
Operation
at Constant Displacement
I
Constant Acceleration Level.
This type of operation
can
be obtained by using
either
an
accelerometer
or
a velocity type pick-up, or
both,
as the
controlling element.
The frequency and level ranges available, when the different types of
control
are
used are best illustrated by means of three diagrams
,
see
Fig. 8.
Fig. 8a shows the frequency and level ranges which
can
be utilized when
an
accelerometer is used as the
controlling
element only.
Fig. 8b shows how the ranges are
slightly changed
when a velocity type
pick-up is used to
control
the table motion.
Fig. 8c shows the operating ranges when a velocity type pick-up is used for
displacement control
(i.e.
below the cross-over frequency), and an accelero-
meter is used for acceleration
control (i.e.
above the cross-over frequency).
To set up the test the following procedure may be
applied:-
20
Advertisement
Table of Contents
