Screening
Services and Training
Last
Update 4/14/2006
25092 Natama Ct
This
procedure is based upon a
paper written by Screening Systems, Inc.
Laguna Hills, CA
92653-5607
How to: Setup
and Run the Vibration Table “TEST” Capabilities of
the SSCTM-2000
Controller Software.
The vibration table TEST capabilities are built in to the
SSC-2000 software to enable periodic and diagnostic acquisition,
recording, and
display of individual vibrator operational parameters.
The resulting data file is essential when
troubleshooting suspected vibrator, table, or air control problems. When a suspected problem
occurs the TEST
process should be run and the resulting data file saved as a named file. The file will have a
“.vt” extension.
The following is the preferred procedure to be used when
selecting appropriate variables and acquiring vibrator output data for
diagnostics purposes.
Left mouse on the “Test!”
pull-down menu.
The Vibration Test Mode screen will appear with
the default values for the selectable
variables.
These variables should be changed to the following values so
that the test yields the most data in the least time.
Channel:
Set the Maximum number to the number of
vibrator drive channels used by your system. 
The yellow slide bar found at the lower center of the
Manual Mode screen
normally indicates the number of channels for your system. In this picture, the slide
is at the number
8. Therefore, set
the Channel minimum
variable to 1, the Channel maximum to 8, and the increment to 1.
Multiplier:
Set these variables to 100, 100, 25.
Since the multiplier minimum and maximum are the same, the
variable will
not increment during the test so the increment variable may be set to
any
number within range.
Cycle
Time: Set the Cycle Time minimum and maximum to 190 and the increment
to any
number within its range.
Valve Area:
Set the minimum Valve Area variable to a low value that is high enough
to
assure the vibrators will start. A
typical setting is 75. Set
the maximum
Valve Area variable to 200. This
is the
setting for valve full open. Increment
the Valve Area in increments of 25.
Since the Cycle Time minimum and maximum are set to the same
values, the X-axis Units will default to Valve Area.
The next step is to place the feedback accelerometer
clusters at consistent locations that will be used each time the TEST
is
run. This
will provide comparison data
between runs performed at annual calibration intervals or when a
problem is
suspected. When installing the accelerometer clusters to
match
the sketches below, both the cluster locations and the individual
accelerometer orientations should be followed.
Preferred locations are shown for most standard size tables
built for the model QRS type systems.
Preferred locations for
18” X 15” table.
Preferred locations for 30” X
26”
table.
Preferred locations for 38” X 26” table.
Preferred locations for 44”
X 44” table.
After
verifying that the compressed air is supplied to the system, left mouse
on the
“START” button.
As the test starts the parameters will increment through the
listing of variables from left to right acquiring acceleration data at
each
point.
At the completion of the test a graph of each of the
vibrator acceleration output gRMS values
verses valve setting (area opening) will be
presented.
Each colored line on the plot is the acceleration in gRMS
generated by
an individual vibrator air channel.
Carefully count the lines on the chart to determine if the
accelerometers detected vibration from each of the vibrators. A
channel that did not generate vibration
will cause a colored line to be drawn along the horizontal 0.0 grid
line and
will therefore not be visible.
The colors of the lines may be changed by selecting
"Configure /
Graph" while the Vibration Test Mode screen is displayed.
To save this data, left mouse on the File pull-down menu and
select the Save As option.
When
“Save As” is selected the standard Windows
“Save
Vibration Test File As” panel appears and the operator is
prompted to enter a file
name with the default “.vt “ extension.
To view a previously saved .vt file, select File\Open\Vibration
Test(*.vt) and select the file. After
it loads, left mouse the “NEXT” button at the lower
center of the screen. This
will redraw the graph lines.
For technical assistance contact Screening Services and
Training via e-mail. mailto:scrserv@cox.net
