Rockwell Automation 1440-VLF02-01RA XM-121 Absolute Shaft Module - Manual (Page 145)

Publication GMSI10-UM014D-EN-P - May 2010
Guidelines for Setting the Full Scale Value 137
Example on Using Table The following example shows you how to use the Full Scale table to determine
the optimal Full Scale value.
To determine the optimal Full Scale value, follow these steps.
1. Refer to Table D.1 XM-121A Measuring Case Absolute with
Accelerometer (100 mV/g) on page 136.
2. Under the Maximum Vibration Level column, select the row that
corresponds to 10 mils.
3. Under the 4 Hz High Pass Filter (HPF) column, find the recommended
Full Scale Setting. The recommended Full Scale Setting for the 4 Hz
High Pass Filter is 0.012.
4. Refer to the value under the Max High Frequency Peak Amplitude
column to verify that there are not any signals present at the sensor that
exceed this value. For the example above, the Max High Frequency Peak
Amplitude value is 4 g’s.
If there are signals in excess of this level then increase the Full Scale
value to the next higher Max High Frequency Peak Amplitude value,
0.08 in this example. If there are no extraneous signals that exceed this
value then proceed with setting the Full Scale at the selected value, 0.012
in this example.
EXAMPLE
Application: XM-121 Absolute Shaft module with
100 mV/g accelerometer
Units used for monitoring: case absolute, ips or mils
High pass filter: 4 Hz
Maximum vibration level: 8 mils pp
TIP
Since the maximum vibration level of 8 mils is
greater than 5 mils, it is necessary to refer to the next
higher level in the table, which in this case is 10 mils.
IMPORTANT
Step 4 is necessary only in applications where an
acceleration input is integrated to velocity (ips, mm/s) or
displacement (mils, µm) and where high frequency
(>5 kHz) acceleration signals are likely present.