E
Vibration measurement
E:17
Enveloping filter
Enveloping is a technique used to detect low energy
vibration typically caused by gear and bearing
damage. This type of damage tends to modulate the
amplitude of high frequency vibration, e. g. at the
natural frequency of the transducer.
To suppress all vibration in the lower frequency
ranges, a high pass (HP) filter is set at 1000 or 2000
Hz (1). To suppress vibrations in both the lower and
the higher frequency ranges, select one of the band
pass filters (Filter 1- 4).
Quick mode
‘Quick mode’ (2) is used to speed up the measure
-
ment. The measurement calculations will be based on
the FFT instead of the time signal, resulting in faster
data acquisition time.
Quick mode can not be combined with enveloping,
time signal or condition parameters (Crest, Kurt,
Skew, NL1 to NL4).
Average type
To achieve greater accuracy, one can order the
average result (3) from a stated number measure
-
ments (average count, set on the number pad). 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 posi-
tion. ‘FFT linear’ gives the mean value of the measure-
ments, while FFT peak hold gives the maximum value.
Average overlap
To achieve faster collection of measuring values,
one can set ‘Averge overlap’ (4) to 25% or 50%. This
function reduces the measuring time by using less
time waveform data to produce the spectrum.
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Summary of Contents for leonova emerald
Page 1: ...User guide PORTABLE EFFICIENCY ...
Page 2: ......
Page 6: ...A 2 General instrument functions A ...
Page 36: ...B 2 General measurement functions B ...
Page 74: ...C 2 Measurement techniques always included B C ...
Page 88: ...D D 2 Shock pulse measurement ...
Page 122: ...D D 36 Shock pulse measurement ...
Page 124: ...E E 2 Vibration measurement ...
Page 150: ...E E 28 Vibration measurement ...
Page 152: ...F F 2 Rotor balancing ...
Page 170: ...F F 20 Rotor balancing ...