What are Laser Trackers?

Laser trackers are large-scale measuring devices that use a laser beam, a gyro, and rotary encoders. A laser beam is fired at a retro-reflective target to measure distance and angles, allowing the tracker software to compute an X, Y, and Z position of the target in 3D space.

Laser trackers use either absolute distance measurement (ADM) or interferometer technologies to measure distances from the laser tracker, with most trackers using only ADM systems.

How to use a laser tracker

Laser trackers are just like any other tactile measuring tool. The spherical-mirrored retroreflector (SMR) becomes the probe that contacts the surface to be measured and the laser tracker measurement is triggered taking a 3D point in space.

Laser tracker software

Laser trackers are used with probing software for tasks such as inspection and tool building. A point cloud software package is also necessary if a laser scanner is used in conjunction with a laser tracker.

Typical laser tracker package

  1. Laser Tracker
  2. Mounting tripod or stand
  3. Software and laptop computer
  4. SMR target/s, probing or scanning system (optional)

Why do we need a laser tracker?

Laser trackers are beneficial for measuring large objects inaccessible and remotely located, such as mining equipment in-situ.

The laser tracker can be located at a distance of up to 80 metres from the structure being measured.

Large volume inspection with laser trackers and alignment tasks in the mining, aerospace, and power generation sectors are common and allow the measurement of large tooling fixtures, large components in-situ, and during maintenance and shut-down periods.

large volume inspection with laser trackers helps improve productivity in energy and mining sectors
large volume inspection with api laser trackers

What are the main applications?

  • Laser trackers allow maintenance crews in the power generation industry to accurately measure large parts in-situ rather than having to move them, saving substantial amounts of time in the shut-down schedule.
  • Typically laser trackers are used for measuring large and complex jigs and fixtures or tooling used in the fabrication of aircraft components such as wings, ailerons, and rudder sections, as well as in the assembly of aircraft sub-assemblies to align large and difficult to maneuver sections of aircraft accurately.

API Laser Trackers

API’s founder Dr Kam Lau developed laser tracker technology over 30-years ago, and now with a new improved and rationalized range of RADIAN laser trackers API is focused on showing customers in Australia and New Zealand how these systems can improve productivity and enhance quality in many applications and markets in the region.

The benefit therefore in choosing an API laser tracker is that you are dealing with the originators of the technology and a manufacturer who is solely focused on the further future developments of laser tracker systems.

Met Optix is proud to be API’s sales and support partner in Australia and New Zealand for API’s outstanding range of laser tracker systems.

API laser tracker models


Target Systems:
Active Target

Probe and Scanning Systems:
iSCAN and vProbe

SMR and Accessories:
Laser tracker SMR range, target Tooling, tripods, and software

See API laser tracker range
Large volume inspection with laser tracker
Large volume inspection with laser tracker

Which model should we choose?

RADIAN CORE is an entry-level laser tracker that enables uses to measure large parts and structures and parts with an ADM-only system and when API’s probing system are not necessary or envisaged being needed in the future.

RADIAN PLUS is a versatile laser tracker with ADM-only capabilities and ranges up to 80 meters and when optional API probing systems such as V-probe may be required or when the SmartTrack system may be necessary.

RADIAN PRO is the premium API laser tracker with both ADM and IFM technologies available and when higher accuracies are required. It is the only API laser tracker that operates with the optional SmartTrack 6DoF target system for complex machine tool calibration and verification tasks.

Support for laser trackers in ANZ?

The range of services offered starts with basic technical telephone and consultation and progresses through on-site calibrations, repair, and maintenance. Finally, more complex tasks such as machine or equipment upgrades complete the picture.

By only supplying the highest quality products, our customers can be confident that their measurement results will be accurate and repeatable; high-quality measurement systems are critical to achieving consistency in measurement goals.

Contract measurement

Large volume inspection with laser trackers is a key part of our contract measurement services when you need extra measurement capacity or assess new measurement technologies before purchase.
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Calibration & verification

Rely on annual equipment calibration or verification from factory-trained personnel to maintain the accuracy and repeatability of your valuable metrology equipment.
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Software support

Software is essential for the operation and data collection for most of the metrology products that we sell. Make sure that you can rely on great support and help with your software.
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Get training to acquire or enhance skills on metrology software and measurement systems in order to maximize the return on your investment.
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Have a new application in mind?

Let’s discuss some options?
APIlaser tracker July 2020 Newsletter

API Virtual Showroom!

In these testing times, API Metrology is working hard to exhibit its award-winning range of metrology products to potential customers.

Click on the link below to access API’s virtual showroom for details on their latest products and success stories.

API laser tracker range

API has rationalized its laser tracker range down to three models, the Radian Core, Plus, and Pro with ranges from 20 meters to 80 meters. The Radian is the smallest, lightest, and most portable laser tracker on the market and operates with any external controller (except for the Pro model) with WiFi connectivity.

Available in both ADM only and ADM and IFM technologies (Radian Pro), the API range leads the market in innovation, technology, and functional design.

The API laser tracker range is complimented with two target systems, the Active Target system, and the API SmartTrack with its 6 degrees of freedom measurement capability.

API ex-demo laser trackers!

API has a number of ex-demo laser trackers that have been used previously by API’s contract services group. These trackers are now available for resale and have been fully refurbished, calibrated and offered with a one-year factory warranty.

These refurbished API laser tracker systems represent outstanding value.

Latest technology

Laser trackers work by measuring the radial distance from the tracker to the target and the zenith and azimuth angles.

The angles are measured by angular encoders and the radial distance measured with either an interferometer (IFM) or an absolute distance meter (ADM) or a combination of both.

Historically laser trackers started out using IFM, but as improvements in ADM technology occurred, many systems became ADM only and now only a small number of systems have both IFM and ADM in one device.

IFMs work by splitting the laser beam into two parts: one beam travels directly to the interferometer, while the other travels to a target device in contact with the component being measured.

The two lasers interfere with one another inside the interferometer (hence the name), resulting in a cyclic change, each time the target device changes its distance from the tracker.

ADMs use infrared light from a semiconductor laser which bounces off the target device and re-enters the tracker. The infrared light is then converted into an electrical signal for time-of-flight analysis.


IFM has a fast update rate and it has been the industry standard for the last 30-years. The weaknesses are that it cannot determine its absolute position without a starting point and requires an uninterrupted line of sight between the tracker and the target.

ADM systems can measure distances without an absolute starting point and the laser beam can be interrupted without disrupting a measurement. Its, however, less accurate than IFM and its speed is restricted by integration time.

Software Options

  • Verisurf CAD/Measure
  • Verisurf BUILD

What else do we need?

As well as the laser tracker, software and laptop computer, other items are needed to make the laser tracker package complete. These items include SMR or target systems, tooling kits, calibration tripods and stands for the laser tracker.


For the range of portable measuring Arms that we sell, we recommend and support software packages from Verisurf.

Depending on the intended applications such as inspection, reverse engineering or both and whether a laser scanner is proposed, there are a number of options with Verisurf.


When choosing a portable measuring arm system, consideration should also be given to the additional accessories that will be required such as the method of mounting the arm and extra probes.

The methods of mounting portable measuring arms range from a simple magnetic base to folding portable tripods to rolling stands for ultimate stability and accuracy.

Tooling kits

Fixturing is important to ensure repeatable measurements and so that CMM programs have a consistent reference point from which to start. Fixturing includes:

  • Lok-N-Load fixturing systems or
  • Custom-design fixtures

Laser tracker targeting and probing systems

Large volume inspection with laser trackers is made easy as API laser trackers communicate seamlessly with a range of target systems and probes, including the new vProbe, Active Target and SmartTarget systems for use in a wide range of applications such as the surveying of large structures, machine tool alignment and controlling robotic assembly systems.

Latest generation vProbe


Hand-held, light-weight, wireless tactile probe with easy-hold grip stylus allows for inspection of intricate features & cavities for large, complex parts.

API vProbe

API Active Target system

Active Target houses a break-resistant SMR(spherically mounted retroreflector). SMRs track over 80m in range with accuracies of ± 2.5 microns. SMRs offer high accuracy line of sight measurement.


Scan up to 200,000 points per second

Hand-held, light-weight, wireless tactile probe with easy-hold grip stylus allows for inspection of intricate features & cavities for large, complex parts.

Need more information?

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