QuickCollect CMDT 391 / CMDT 391-Ex
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User Manual
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Revision B
Velocity
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Vi ratio elo it is o sidered the ge eral purpose i ratio
measurement for detecting machinery problems. This is because most machinery
problems generate low to mid-frequency sinusoidal-type vibration signals (problems
such as imbalance, misalignment, bent shaft and looseness), and velocity
measurements focus on detecting vibration signals occurring in this frequency
range. ISO standards provide general guidelines for vibration severity using velocity
criteria.
Enveloped
acceleration
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Rolling element bearing faults cause low-amplitude
impulsive -type vibration signals at a regular rate of repetition. When monitored
using velocity measurements, these low-energy impulsive signals are typically lost in
surrounding machinery vibration noise caused by imbalance, misalignment,
looseness, etc. Enveloped acceleration measurements filter out surrounding
machine vibration noise and enhance the impulsive nature of repetitive rolling
element bearing or gear fault vibration signals, allowing much earlier and accurate
bearing fault detection. Not used for overall machine vibration monitoring,
enveloped acceleration measurements ensure consistent early detection of bearing
and gear-type defects.
Measurement and analysis capabilities
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When the sensor is used in conjunction
with the SKF ProCollect app and SKF Enlight Centre the available sample rates
(bandwidth) and FFT resolution are extended and adjustable.
QuickCollect Sensor - Temperature
Temperature measurement is a useful indicator of mechanical condition or the load
applied to a specific component. As a bearing or its lubrication fails, friction causes its
temperature to rise. Measuring temperature changes at the bearing helps the early
recognition of problems and the scheduling of corrective maintenance before a serious
and expensive failure occurs.
The sensor
s
opening for taking temperature measurements is located next to the
magnet mounting, Figure 2
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6 below. The infrared (IR) sensor has a range of 4 cm and
quickly determines the temperature of the equipment to which the QuickCollect sensor
has been attached. Note that the temperature measurement is unavailable when the
external sensor cable is in use.
Figure 2 - 6.
IR sensor location.
