science

Laser tracker

Laser tracker is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Laser tracker rather than just read about it. In short: Laser trackers are instruments that accurately measure large objects by determining the positions of optical targets held against those objects. The accuracy of laser trackers is of the order of 0.025 mm over a distance of several metres.

Key takeaways

Laser tracker belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Laser tracker to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Laser tracker from memory before moving on to harder problems.

Reference excerpt

Laser trackers are instruments that accurately measure large objects by determining the positions of optical targets held against those objects. The accuracy of laser trackers is of the order of 0.025 mm over a distance of several metres. Some examples of laser tracker applications are to align aircraft wings during assembly and to align large machine tools. To take measurements the technician first sets up a laser tracker on a tripod with an unobstructed view of the object to be measured. The technician removes a target from the base of the laser tracker and carries it to the object to be measured, moving smoothly to allow the laser tracker to follow the movement of the target. The technician places the target against the object and triggers measurements to be taken at selected points, sometimes by a remote control device. Measurements can be imported into different types of software to plot the points or to calculate deviation from the correct position. The targets are known as "retroreflective" because they reflect the laser beam back in the same direction it came from (in this case, back to the laser tracker). One type of target in common use is called a spherically mounted retroreflector (SMR), which resembles a ball bearing with mirrored surfaces cut into it.

History The first laser tracker was invented in 1987 by Dr. Kam Lau, CEO of API (Automated Precision, Inc.) while at NIST and made commercially available by API Metrology in 1988 with its first production unit being made available to Boeing under a 9-month lease agreement. Tennessee Technology University received an API 6-D laser tracker in 1989. Instruments were later produced by Kern in 1991 following a technology agreement with API. Currently, there are three well known manufacturers of Laser Trackers; FARO, API, and Leica.

Footnotes

References and sources Bob Bridges. “How Laser Trackers Work.” Quality Digest, June 25, 2009. James R. Koelsch, “Should Laser Trackers be in your Arsenal of Metrological Tools?” Quality Magazine, March 2012. “Portable laser tracker measures large volumes accurately.” Machine Design, August 25, 2011, Vol. 83 Issue 14, p19. Joel Martin. “Laser tracking fundamentals.” Quality Magazine, May 2007. Javier Vera. “The Versatile Laser Tracker.” Quality Digest. January 27, 2011. National Institute of Standards and Technology. "[1] Archived 2018-11-26 at the Wayback Machine." "NIST Public Affairs Office", June 4, 2010.

Illustrations

Worked examples

Example 1 — a first encounter with Laser tracker

Start with the simplest possible case. Write down what Laser tracker claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Laser tracker before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Laser tracker ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Laser tracker

In research: Laser tracker appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Laser tracker in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Laser tracker is common in secondary-school and first-year university syllabi. It links to neighbouring topics 3D imaging, Laser image acquisition, Metrology, so understanding it makes those chapters shorter.
In everyday life: Look for Laser tracker outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Laser tracker in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Laser tracker means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Laser tracker out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Laser tracker in simple terms?

Why does Laser tracker matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Laser tracker?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Laser tracker.