|
The fact that machinery moves during operation
is established and well documented. Many manufacturers of rotating
equipment provide expansion data for their products derived from
theoretical calculations. It is Precision Concepts position
that no matter how painstakingly careful one is in approaching these
calculations, and no matter how sophisticated the mathematical approach,
unavoidable limitations are encountered when applying pure theory
to field situations. Further, thermal growth is not the only contributor
to positional change of on-line machinery.
A good alignment target
takes all significant factors into account. The objective is to
deliberately misalign the machine assembly off-line so that it runs
into a "straight line" when activated. Occasionally, the
solution to thermal growth problems require expansion joints or
additional securing of pipes. Nevertheless, the problem with on-line
monitoring is: "How do I get realistic data"?
Laser technology, when employed correctly,
limits the human element to the most fundamental task of setup.
With all measuring tasks being performed by a transducer linked
to a data collector (personal computer), Precision Concepts
rotating equipment specialist's have the chance to concentrate on
the process rather than measuring tasks. Fixtures are kept to minimal
sizes, thus reducing the chance for uncertainty of measurements
via systematic error in bracketing. Sag is not a consideration with
lasers.
|
