The key to effective Condition Monitoring (CM) is to
understand CM itself before looking at the individual
monitoring techniques. Equipment not being fitted correctly
or machines not being used for their original purpose are
examples of problems that can lead to false readings and a
poor understanding of what is happening inside a plant. Ian
Pledger, field service engineer at Schaeffler (UK), explains

The first thing you need to have is a
good relationship between the
engineers on the plant and your CM
partner. There is little point in doing CM if
the actions you recommend are not followed
up. Second, don’t try to do too much too
soon. It is important to build up the portfolio
slowly but effectively so that everyone is
onboard at the outset. Third, you need to
decide if you are doing the CM yourself,
whether you have a dedicated CM workforce
or if you are going to do CM as an ad hoc
activity. The latter is difficult because CM is
not always a priority role for many engineers
who are pulled in so many different
directions and have limited resources.

However, if implemented correctly, many
engineers will be able to avoid a ‘firefighting’
culture and benefit from a
‘prevention is better than cure’ approach.

Once these foundations have been laid, it
is then a case of deciding on the right tools
and techniques for the plant being
monitored. There is little point in trying to
fit the plant to the CM equipment. The CM
equipment must be aligned to the plant. The
one tool or technique that makes the
difference is always the one that works best
for the application or environment in
question. For example, vibration monitoring
is best suited to monitoring high speed
applications because it is easier to obtain
more detailed information compared with
acoustic emission (AE) monitoring
techniques, which are more suited for slow
rotating equipment generally above 80rpm.

The latest CM systems are being used to
monitor a diverse range of industrial
equipment, including pumps, motors and
compressors.

Schaeffler’s latest CM device for example,
FAG SmartCheck, is an ultra compact device
that can be used to monitor vibration and
temperature, as well as a range of other
machine and process-specific parameters
such as pressure and flow rate. By
monitoring these parameters, users are
provided with a broad basis of information
in real time, which enables the accurate
assessment of machine condition. Due to its
patented self-learning (Teach-In) mode, the
device’s alarm thresholds are adjusted
automatically. After set up and commissioning,
the unit operates autonomously. The relevant
machine parameters are measured and saved
continuously in the system, creating a
substantial database over time.

Bearing defects in electric motors can be
detected early by monitoring vibration and
noise levels. German company Schorch
Elektrische Maschinen und Antriebe, for
example, required a reliable, cost-effective
method of monitoring its motors, in terms of
both monitoring bearing damage and other
parameters such as temperature, load and
speed. This comprehensive source of data
would provide continuous information about
the overall condition of machinery, including
difficult-to-access machines or ones installed
in remote locations. In order to provide
information about the long-term condition
of machines in the field, access to historical
data was also needed. Schorch installed a FAG
SmartCheck device on the drive motor of a
piston compressor. Further parameters such
as room temperature and motor housing
temperature were recorded and correlated
with the vibration signals to enable
intelligent process monitoring. However, the
customer’s main priority was the vibration
measurement results, which gave an early
indication of any damage to rolling bearings.

Other OEMs are also benefiting from CM,
for example, on vacuum pumps, FAG
SmartCheck can help to identify imbalances,
incorrect shaft alignments and bearing
damage. These critical operating conditions,
if left undetected, could lead to the stoppage
of a complete production line.

Due to their flexibility, CM devices can be
attractive solutions for machines that are
installed in remote locations, for example,
flood control pumps in reservoirs. Here,
measurement data from the pumps can be
accessed remotely using secure, remote
Internet connections. Operators are
permanently informed about the condition
of their machines without having to be onsite
and if necessary can take immediate
counter-measures if alarm thresholds are
exceeded.

CM devices are also being used
successfully to monitor the condition of
compressors, which are often subjected to
heavy loads and considerable vibrations,
which means unplanned downtimes can
occur suddenly without warning. By
installing CM systems, it is possible to reduce
these risks.