SPM leonova emerald, Руководство пользователя

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Shock pulse measurement
Variable speed
The alternative ‘Variable speed’ (1) implies that the shock
pulse measurement is preceded by a measurement of the
rpm.
Measure RPM simultaneously
‘Measure RPM simultaneously’ (2) is normally not used. With
this setting on, you are forced to measure the rpm simulta-
neously with the shock pulse measurement
Measuring time
Depending on the rpm of your application, the Measuring
time (3) setting has a significant impact on the length of a
measuring cycle. Empirical studies have shown that in order
to achieve reliable measurements of bearing condition,
measurement should cover
at least 10 shaft revolutions
and preferably 50 revolutions, which is the default setting.
The time required to complete a measuring cycle can be
calculated as 50 X (60/RPM).
FFT calculation
This setting means that a full SPM HD measurement including FFT will be saved. Input upper frequency
in orders and number of spectrum lines. Under ‘Save’, select ‘Time signal and FFT’, ‘Full spectrum’ or
‘Condition parameters’ to be saved with the measurement.
Symptom enhancement factor
The ‘Symptom enhancement factor’ (4) is used to improve the signal-to-noise ratio. For applications
with little electronic noise and few mechanical shock phenomena, this factor can be kept low (0 - 5).
Where noise and random shocks are frequently occurring, it is recommended that the ‘Symptom
enhancement factor’ be set to 5 -10. However, you should be aware that the higher this factor, the
longer the measurement cycle. The Y axis unit in spectrum and time signal is HDesv when symptom
enhancement is used.
Time synchronous averaging
To achieve greater accuracy when measuring gear damages, 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.
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 RPM trigger can be used on
applications where useful readings can be obtained only within a limited RPM range, such as in cranes.
The purpose of the ‘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’ can be set to ‘RPM run up’ or ‘RPM run down’. ‘RPM run up’ means Leonova 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. With ‘RPM run down’, Leonova waits for RPM to slow down to
the ‘Trigger level’ setting.
When using ‘Post trigger’, input a value (HDsv) under ‘Trigger level’. In the above example (5), Leonova
will initiate an SPM HD measurement and wait for the signal’s HDsv level to reach 25 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.
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