COUPLING AS- 4322070 - Caterpillar

Analysis Parameter Set (APS)
As stated above, certain features are common to all route points in the database. Only the variable features of each of the Analysis Parameter Sets will be discussed in detail in this manual.Seven stored features of the data (known simply as the PARAMETER SET when displayed by the analyzer) are influenced by the APS. These are the OVERALL value and six other parameters. The OVERALL value is always stored and the APS simply determines the units and the range of frequencies (bandwidth) included in the value.The six parameters are defined by label as to what they represent along with the units and bandwidth. They are usually labeled as either orders or frequency bands. The exception is in APS 23 which has 2 parameters labeled as OVERALL DISP and OVERALL VEL.Table 1 is a summary of all of the ANALYSIS PARAMETER SETS which shows those parameters which are not common to all route points.Alarm Limit Set (ALS)
The ALARM LIMIT concept is oriented primarily toward the predictive maintenance application of vibration measurements. However, the alarm limits can also be useful in diagnostic work because they can be used to highlight a spectral component that may require further investigation. Table 2 in the Table Information Section shows the Alarm Limits for each of the Alarm Limit Sets included in the Database LIN33.DAT.When attached to a route point, the alarm limit signals the user by displaying a message if a parameter value is equal to or higher than that set to trigger the alarm. This is demonstrated in Illustrations 9.
Illustration 9.Illustration 10 shows a typical LCD display at the completion of data collection on a route point. Note the STATUS=OK message which indicates that no alarms were triggered.
Illustration 10.Illustration 10 shows the LCD when an alarm has been triggered. The message now is STATUS=VIB. ALARM which indicates that some predetermined level has been met or exceeded. To find out what triggered the alarm, the user must display the stored parameters.The analyzer determines the OVERALL value by calculating the square root of the sum of the squared values of all the spectral components over a specified frequency range. In the case of an order based APS, this is determined by a specified low frequency and the frequency of the highest specified order at the measurement RPM.Example: At 1800 RPM, the OVERALL