Do
you have a part that you need to inspect but is too big to move, or too big to
fit into your coordinate measurement machine? Perhaps it’s an in-process, part
that needs to remain on the machine tool?
Well,
don’t fear there is a solution to overcome your obstacles…laser trackers; fast,
accurate, in-house test, measurement and inspection tools for large-volume
products.
Laser
tracking is a technology that has been around for about 30 years, but it is now
more accurate, capable, and robust than ever before. These line-of-sight
devices are extremely appealing because of their portability, repeatability,
and accuracy.
The Technology
Laser
tracker technology is based on the combination of two techniques: a distance
meter to measure absolute distance and angular encoders to measure the tracker's
two mechanical axes--the azimuth axis and the elevation (or zenith) axis.
Laser
trackers emit a low-power, eye-safe laser beam (Class 1) to a retro reflective
target that is either held or mounted on the object to be measured. The laser
light reflects off the target and re-enters the tracker, as it re-enters the tracker
a distance meter analyzes the light and measures the distance from the tracker
to the target. As the retro-reflector is moved, the laser tracker records the
distance, azimuth and elevation.
The
tracker can be directed to take data points at regular intervals such as every
few thousandths of an inch. It can measure points continuously, so data can be
gathered on critical parameters like thermal growth. Powerful software stores
these values and compares the data to uploaded CAD files.
Laser Trackers vs. Other
Measurement Tools
Laser
trackers can capture large volumes of 3-D coordinate data quickly and in real-time. They can be moved easily and can be
installed in a variety of configurations to get the best angle. Unlike
rooted to-the-floor CMMs that have a limited work envelope, are best in
environmentally stable conditions, and must have the parts transported to them;
laser trackers can be brought to the part, are robust enough to withstand many
environmentally challenging conditions, and can track enormous parts.
But,
you ask, how about my portable arm CMM? It can move to the part and be used to inspect hidden areas. Yes, while
portable CMMs are fantastic quality devices with more flexibility than
stationary CMMs or handheld gages, where they cannot compare to laser trackers is
in the size of the parts to be measured and accuracy.
Portable articulating arms are accurate to approximately
0.0002 in. (new models being accurate up to 0.0007 in.) that is, in nice, clean
environments, but not all shop floors are nice, clean environments.
Laser trackers on the other hand are accurate up to 0.0006 in. (0.015mm). Another strength of the 16-inch, 28 pound, IP52 rated laser tracker its ability to
be used in a wide range of conditions as it is resistant to shock, vibration,
temperature cycling, and humidity. It also continuously monitors temperature,
air pressure, and humidity and compensates accordingly to ensure accuracy.
So,
for accurate, consistent, and repeatable measurement data of very large parts
that won't work on your CMM, laser tracker technology can be the answer.
Inspec
now offers laser tracker services in addition to add to its other inspection and
metrology solutions.
Learn more about
laser tracking in this video or contact Inspec to see how they can help you
solve your measurement obstacles.