Laser trackers are great instruments for accurate measurements over tens of metres. That said - like many metrology instruments - it is easy for “bad” data to be acquired. One of the largest sources of error can be attributed to poor working practices. Poor working practices lead to large variations between operators, and an overall loss in confidence in the measurement system as a whole.
Here are three, low cost (and mostly free) ways to improve your laser tracker processes.
1. Understand the System
You should aim to understand the variation in your processes - without knowing this, it will be hard to isolate the weaker areas that might need improvement. Simple type one studies, measurement systems analysis, and gauge repeatability and reproducibility (GR&R) studies can give much needed insight as to whether the system is sensitive to the manufacturing variation, whether measurements are consistent between operators, or even if the measurement system is repeatable in that application. You ultimately want to know whether the system will give the same answer regardless of the operator who uses it, and that it is sensitive enough to pick up the levels of manufacturing variation that your production system might exhibit.
2. Subscribe to Operator Training & Good Practice Principles
Once the laser tracker has been “proven”to be a suitable tool for the job, the next step is to ensure consistency between operators. This can only come about through a coherent training programme that focuses on measurement application. Training is often delivered as “hardware” or “software” but metrologists have to use both in conjunction in order to take effective laser tracker measurements. Bespoke application-based training for operators or metrology teams, provided by specialists such as INSPHERE, has huge benefits.
Training operators in good practice principles can be a quick win; for example, by encouraging regular and consistent field checks, ensuring drift checks take place, or standardising the strategies for feature measurement, the measurement data will be more consistent and robust within an organisation.
3. Maximise the Potential of Your Software
Many measurement software platforms have ready-made solutions for ensuring good practice. However, further consistency can be added by utilising the automation features within your software platform; this could be as simple as ensuring features are measured with the same number of points each time, or a guided inspection routine. Automation can also be much more involved, for example, using fully automated measurement and alignment scripts can ensure the process is done "exactly" the same each time.
By adding some simple good practice steps into your laser tracker measurements and processes, you can greatly improve the quality of measurement, reduce variation, and increase measurement confidence in your data.
INSPHERE are experts in dimensional measurement and provide solutions to simplify and increase the productivity of measurement processes. We provide measurement automation solutions, sub-contract services, measurement training and consultancy across a range of industries including aerospace, energy, marine and automotive. Contact us for more information on how our expertise and best-practice measurement approaches can help your company.