PAGE 4
MANUAL NUMBER: 18295
MANUAL REVISION: B
Figure
2:
Cross-Section
of
Handheld Shaker Vibration Head
A section view of the shaker’s vibration head is shown in
Figure 2
. The
shaker consists of an electromagnetic exciter, driven by an oscillator at a
frequency of 159.2 Hz (1,000 rads
-1
). A small ICP® accelerometer
provides a servo feedback to maintain a constant vibration level of 1 g.
This enables accelerometers with masses up to 7.4 oz (210 grams) to be
exited without their mass influencing the reference level.
Operation
Model 394C06 is a precision instrument and when being used to check the sensitivity of sensors, should be
verified prior to use with a reference standard. Use of the shaker is straightforward. Attach an appropriate
accelerometer to the shaker using the supplied 10-32 Be-Cu stud or other hardware. The shaker is supplied with
adapter mounting studs from 10-32 to a variety of standard and metric threads including the flat pad for adhesive-
mount sensors (
See specification sheet for current list of supplied accessories
).
With the accelerometer mounted to the shaker, push the On/Off button (
See Figure 1)
. The unit will turn on and
internal power to the shaker will be ramped up providing a smooth, gradual increase in vibration amplitude. This
process prevents shock-induced overloads to the test sensor. A special reference sensor within the unit
constantly measures the g level and internal controls adjust the shaker magnitude to maintain 1 g output while
maintaining the frequency of 159.2 Hz. A relatively stiff suspension is used within the shaker that supports any
sensor up to 210 grams. The output indicating instrument should now be reading the relevant reference value
related to the 1 g input. If reference value is not as expected, check cable connections, consider validating ICP
®
sensors for turn-on with a battery powered signal conditioner (model 480C02). Following the system adjustment,
the shaker is switched off by pressing the On/Off button a second time.
The 394C06 shaker i
s powered by four (4) “AA” batteries in a removable pack / module (model number 073A15).
Battery replacement is simple, rotating the lower section of the shaker counter clockwise will expose the battery
pack. To prolong the life of the batteries, model 394C06 automatically switches off after 90 seconds. New battery
life depends on the mass applied, estimated between 320 test cycles with a 2 gram mass and 80 cycles with a
210 gram mass.
