How Do Laser Trackers Work?

Laser trackers are highly versatile dimensional metrology or measuring devices with applications ranging from high-precision fabrication to construction and engineering. With an accuracy of 0.025mm over several meters, laser trackers are valuable for industries where precision is crucial for maintaining quality and performance standards.

How do laser trackers work? What are laser trackers used for, and which industries benefit the most from them? We answer these questions in this blog.

How Do Laser Trackers Work?

Laser trackers have two critical components: the tracker that emits the laser beam and a retroreflective target (or simply a reflector). 

The function of a laser tracker can be simplified this way: it measures angles, distances, and coordinates by tracking the location of a retroreflective target held against the object or site that needs to be measured by a metrology company

Laser trackers treat their surroundings as a three-axis coordinate plane, with the tracker being the point of origin (where x, y, and z values are at 0). The tracker is mounted on a tripod or stand, and it can swivel, allowing it to measure points 360 degrees around it horizontally and 130 degrees vertically (some trackers may have higher or lesser limitations for the vertical axis depending on the year the model was made or the technology used to build it). 

A laser tracker has a maximum distance it can measure, often 35 or more meters away in every direction. The distance determines the expanse of the coordinate plane that the laser tracker can reach. It can only measure distances within this plane.

So, how do laser trackers work? Here’s how:

  1. The tracker releases a laser beam toward the retroreflective target.
  2. The laser light bounces off the target and retraces its path to the tracker.
  3. The built-in distance meter determines the distance the laser traveled from the tracker to the target. 
  4. The tracker will also calculate angles respective to the target’s position. 

The precision and speed of obtaining the measurements can vary according to the types of components built into the devices. The next section discusses this further in depth. 

Types of Laser Trackers

We can classify laser trackers into two types based on the distance meter formats:

  • Interferometer – Laser trackers with interferometers use two or more light sources to create an interference pattern, which the device will then analyze and measure. Interference patterns resemble water ripples when throwing stones on a placid lake. Each stone generates concentric waves that intersect one another, creating new waves (sometimes none) that show a visible pattern. Light waves behave the same way, and interferometers analyze these patterns to measure distances between points.
  • Absolute Distance Meter (ADM) – This distance meter is more straightforward: it aims for the target and shoots a light beam. The ADM calculates the distance based on the time it takes for the reflected light to reenter the tracker. 

Early iterations of laser trackers had slow ADMs, so it became standard practice for manufacturers to install an interferometer to ADM laser trackers. Some removed ADM entirely and only used interferometers to ensure fast and precise measurement-taking.

However, manufacturers made significant leaps with the ADM in recent years, making them highly reliable for high-speed scanning. As such, you can expect ADM trackers made in the last couple of years to meet high speeds and performance metrics, while older ADM laser trackers might not perform as impressively.

What Are Laser Trackers Used For?

Laser trackers with incredible measuring capabilities are valuable for quality control purposes. Here are some examples of how you can use laser trackers:

  • Ensuring alignment for a smooth, efficient assembly process.
  • Performing real-time measurements and quality control checks to ensure production meets standards and validates compliance and quality requirements.
  • Ensuring machines are correctly calibrated during installation and maintenance.
  • Monitoring mechanical machine parts prone to deterioration and damage to ensure they are within operational specifications.
  • Performing volumetric measurements for dies and molds.
  • Reverse engineering or getting precise digital measurements and design information for parts that do not have blueprints or CAD (computer-aided design) drawings.
  • Performing on-site routine maintenance and calibrations on robotic equipment or large machinery that takes so much time to map and measure manually.
  • Inspecting standalone pieces or parts and entire assembly lines.

Given these uses, laser trackers are valuable for the following industries:

  • Aircraft manufacturing
  • Shipbuilding
  • Automotive jig building
  • Construction 
  • Architecture
  • Aerospace and Defense
  • Transportation
  • General manufacturing

Laser trackers do away with tape measures, calipers, micrometers, etc. While useful in many ways, these tools have tolerances and error margins that are too high for comfort. Errors can lead to significant losses of time, resources, and revenue. For example, there is so much at stake in manufacturing aircraft and medical instruments that there is no room for “minor” errors. Precision is crucial in these industries, and laser trackers are instrumental in that.

Eliminate Error Margins with High-Precision Metrology Tools

If you belong to an industry that requires high-precision measurements or want to improve the accuracy and efficiency of your assembly or manufacturing lines, laser trackers can be valuable additions to your operations. And you’re already in the right place, as ATT Metrology Solutions can provide you with high-precision Leica laser trackers.

We carry several models of Leica laser trackers – a brand and line well-known worldwide for their impeccable build, design, and measuring capabilities. Choose from our selection or talk to our specialists to determine which model best suits your needs.

Contact us via phone or email. You may also fill out our contact form and wait for a response from our specialists.

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