SPM leonova emerald - Page 145

E
Vibration measurement E:23
1
Enveloping filter (Hz)
To detect damages or anomalies in different stages,
a number of predefined high pass and band pass
filters are available. The band pass filters are named
filter 1- 4. Filter 1 and 2 are normally used for special
applications and filter 3 and 4 for gear and bearing
damage.
Filter1=5 –100Hz
Filter2=50 –1000Hz
Filter3=500 –10000Hz
Filter4=5000 – 40000Hz
Advanced
Advanced(Yes/No)openstheoption‘Timesynch.
averaging’.
Time synch. averaging (TSA)
To achieve greater accuracy, one can order the
average result from a stated number measurements.
To get a time synchronous average, a tachometer
must be connected which supplies a trigger pulse.
This starts each measurement with the shaft in the
same position. Time synchronous averaging requires
variable speed. Please note that TSA is recommended
for detection of gear faults only, not for bearing
faults.
1
1
2
2
3
Trigger selection
When measuring on variable speed machines, an ‘RPM trigger’
can be used to determine when to start a measurement,
ensuring that it is carried out at an appropriate speed. The
purpose of ‘Post trigger’ is to avoid the recording of irrelevant
signals that may ultimately cause false alarms. It can be used
where strong signals can be expected which are process
related and not attributed to machine damage.
‘RPM trigger’ will initiate the measurement, then wait for the
machine to speed up to the level input under ‘Trigger level’
before it starts recording the signals. ‘Trigger type’ is ‘none’ for
RPM trigger.
Whenusing‘Posttrigger’,inputavalue(HDeu)under‘Trigger
level’.Intheaboveexample(3),LeonovawillinitiateanHDENV
measurement and wait for the signal’s HDeu level to reach 24
before it starts a complete measurement including time signal
and FFT. Make sure you input a viable trigger level; if the level
is never reached, the measurement must be aborted manually.
‘Symptom enhancement factor’ must be off when using post
trigger.
Under‘Delaytime’,youcanspecifyanumberofsecondsduring
which Leonova will delay the start of measurement. This setting
is optional.