5
6.0
COMMON PREDICTIVE MAINTENANCE MEASUREMENTS
6.1 Vibration
Vibration is considered the best operating parameter to judge
dynamic conditions such as balance (overall vibration), bearing defects
(enveloping) and stress applied to components. Many machinery
problems show themselves as excessive vibration. Rotor imbalance,
misalignment, mechanical looseness, structural resonance, soft
foundation, and gear mesh defects are some of the defects that can
be measured by vibration. Measuring the “overall” vibration of a
machine, a rotor in relation to a machine or the structure of a machine,
and comparing the measurement to its normal value (norm) indicates
the current health of the machine.
The EXAMINER 1000 measures the vibration of a machine while it
is operating. Trending these measurements shows how a machine’s
condition changes over a period of time. Analyzing these, along with
other measurements, provide insight into the condition of the machine
and which components may be wearing or failing. How to best monitor
a machine’s condition requires one to know which measurements to
take and where and how to take them. Sensors are placed at strategic
Points on the machinery to monitor the machine’s condition.
The EXAMINER 1000 processes the accelerometer’s mechanical
vibration energy into an electrical signal and displays the measurement
value in numerical form for evaluation. Commonly measured physical
characteristics in Predictive Maintenance are:
•
Vibration (as explained above)
• Temperature
•
Oil Analysis
6.2 Temperature
As a bearing fails, friction causes its temperature (or its lubricant’s
temperature) to rise. While trending a bearing, if the temperature rises
followed by a vibrations increase, then it is safe to conclude there was
