01/09 ·
uptime
m
e
gazine 3
For many years online
machine monitoring was
deceivably simple critical
machines were monitored
by rack-based systems,
and the rest balance-of-
plant machines (BOP) -
were monitored by vibration
monitors.
T
he safety monitoring require-
ments for both types of ma-
chines has been relatively similar,
hence the differentiation in function-
ality between these two products
was minimal. However the gap in
condition monitoring functionality has
been enormous. This was partly due
to cost constraints of the monitors
down, and partly because the condi-
tion monitoring expectations for the
BOP machines was quite low. Most
traditional vibration monitors offer
little more than a buffered output and
a 4-20mA output signal.
A New Generation
of Compact Monitors
FillstheGap
cal if one of the units is taken out for
service. The importance for condition
monitoring of these machines there-
fore increases. A time-based mainte-
nance strategy may be sufficient for
many BOP pumps, compressors and
motors that are operating at a con-
stant speed and a single duty-cycle,
but what about the increasingly more
prevalent flexible industrial processes
that are being implemented in plants
world-wide? Here, switching over to
different process fluids, for example,
may increase plant productivity and
efficiency, but this also consequently
results in different duty cycles and
loading on the machines and hence
different wear rates. This again puts
more importance on the need for ef-
fective condition monitoring.
It was for these reasons why the
"new" generation compact monitors
with advanced condition monitoring
capability were developed. These
monitors offer the same advanced
level of condition monitoring func-
tionality as the rack-based systems
but at a fraction of the cost. The only
difference, is that the compact moni-
tors are cost-effectively dedicated to
specific applications, and therefore
have less functionality. The rack-
based systems, which are intended
for plant-wide applications with many
different types of machines, require
more functionality.
focus
technical
That was the past!
Today there are many machines
that are critical to a process, but
due to physical isolation from other
machines or insufficient sensor input
channels to fill up a rack, they are not
conducive to a rack-based system.
This becomes a dilemma because
the condition monitoring capability of
the traditional vibration monitor is not
adequate for detecting and diagnos-
ing developing machine faults at an
early stage. This dilemma applies to
cooling tower motors, a single train
critical pump, or an isolated gas tur-
bine. Even many spared machines
which are normally monitored by
vibration monitors may become criti-