MN100003 REV A (12/07/10)
Page 7
Inside the VibraCheck Limited & VibraCheck II:
The VibraCheck Limited and VibraCheck II comes equipped with the highest quality components for accurate
and repeatable vibration measurements. In the next sections, we will discuss how measurements are detected,
fi lters and the reasons for having them.
How is the vibration values measured
? Internally, a (RMS) Root Mean Square detector is used to process the
vibration signals. Peak to peak values are computed directly from this RMS value. One of the nice features of
the VibraCheck and VibraCheck II is the ability of the user to select the desired units for measurement, ie. RMS
or Peak to Peak (p-p) for example. Because the VibraCheck Limited and VibraCheck II has smart features, the
user can make vibration measurements using their favorite unit of choice.
Filters:
Each VibraCheck Limited and VibraCheck II has built in fi lters to condition a vibration signal. A
vibration signal whose frequencies are not within the fi lter range will result in null reading or decreased values.
Acceleration: 10 Hz, High Pass fi lter
Velocity:
10 – 1KHz, Band Pass fi lter (conforming to the ISO2954 Standard)
Bearing Condition:
500 Hz to 2 kHz Band Pass Filter
Displacement: 10 – 1KHz, Band Pass fi lter (conforming to the ISO2954 Standard)
Note that the fi lters are forth order, -24dB/Octave roll-off.
