7
7.1.1
Critical Machines
Critical Machines are typically expensive premium equipment
that would have catastrophic health, safety, environmental
or customer-related consequences if it failed. This category of
equipment should be very well maintained and monitored, so
continuous monitoring systems are better suited for this type of
equipment.
Personnel safety is always the first priority in selecting
machinery to monitor
.
7.1.2
Essential Machines
Essential Machines are typically medium size equipment that may
be bypassed economically for a short period of time. Less attention
is typically paid to these machines even though their repair costs can
be as high as critical machines. It is highly recommended to select
some of these machines for your Predictive Maintenance Program.
7.1.3
Redundant Machines
Redundant Machines are typically small size equipment that have
redundancy. This group typically has the largest percentage of all
machines in a plant and yet they are usually neglected. At many
facilities, this group consumes the largest percentage of the annual
maintenance budget. If you want to have an immediate impact in
your Predictive Maintenance Program, begin with these machines.
Also include machines with known problems or a history of problems.
7.2 Selecting Measurements
Establish measurement types that most accurately reflect the condition
of the equipment. Different causes or “mechanisms” are acting on
the machine; various types of measurements have been developed to
measure each type of mechanism. Those mechanisms are:
Stress:
a force on the machine or components which deflects the
part. Best measured in Displacement. The EXAMINER 1000 does not
measure Displacement as it is a very low vibration frequency, below
10 Hz (600 RPM).
