Leica Absolute Tracker AT401

Measure where no other CMM can go

The Leica Absolute Tracker AT401 is a portable coordinate measuring machine (CMM) that allows extreme precision over ultra large distances. It is powered by its own internal battery and is able to work in the most demanding environment, yet maintains the highest level of precision and the largest ever work envelope.

A new level of portability and durability
The complete measurement system weighs less than 15 kg including the case and in a minimum configuration it will fit into the overhead compartment of most commercial airliners. This is truly the world’s most portable CMM

Ready for any environment
Utilizing a completely sealed design that is independently IP54 (IEC 60529) certified means this sensor can be installed in the most unforgiving environments. Spraying coolant, dust, weld splash, nothing is too harsh for this sensor. The Leica Absolute Tracker AT401 is the first laser tracker certified for outdoor use, even in the rain.

PowerLock
Leica Geosystems introduced the world to PowerLock in 2009. This vision technology detects a reflector and automatically locks the laser beam onto it, even when the target is moving. The laser beam moves to the user, not the other way around. In the past operating a laser tracker was almost a “black art”. It took time and experience for an operator to learn how to efficiently use the sensor without breaking the beam. PowerLock changed this completely and makes the handling of a laser tracker much easier.

Cable-less operation
With two identical batteries – one in the sensor, one in the controller- the Leica Absolute Tracker AT401 can run for a work day. When power approaches a critical level, the batteries can be either replaced or hot swapped. The laser tracker continues running as if nothing had happened. With the built in WiFi connection the Leica Absolute Tracker AT401 becomes a completely wireless portable CMM free from any external data or power cable requirements. Optionally the Leica Absolute Tracker AT401 is ready for Power over Ethernet. With this technology, a regular LAN cable supplies the sensor with both data and power.

Ultra Large Volume Measurements
With endless telescope rotation the sensor can measure a full 360° horizon and a 290° vertical dome. Pair this with a typical radial volume of 320 meters and you have the world’s largest volume precision CMM.

Complete system integration
The Leica Absolute Tracker AT401 is ready for any measurement task that comes its way. All accessories such as remote control, environmental monitor or level sensor are already built in.

Feature	Benefit
IP54 sealed	Independently certified IEC 60529 usage in even the most demanding conditions.
Extremely light and compact: 8.1 kg incl. controller, just over 290 mm tall	Measuring where no other laser tracker can go. The controller stays out of the user’s way, e.g. attached to the tripod.
Cable-less design	By combining built in WiFi connectivity and on board battery power, the sensor can operate without any wires connected at all.
Hot swappable battery operation	No need to worry about AC (mains) power - the sensor can run continuously with a new set of batteries able to be swapped in without interruption
Automatic target recognition (ATR)	The ATR allows constant tracking and fine positioning with different reflector types to a typical radial volume of 320 m.
PowerLock beam recovery technology	No need to worry about “breaking the beam”: the tracker automatically locks onto the user providing up to 20% time savings over traditional laser tracker technologies
Proven Absolute Distance Meter technology	The most accurate Leica Geosystems distance meter ever: The ADM has a resolution of 0.1 micron and a maximum uncertainty of 10 microns over a full 160 m radial volume.
Quick Release tribrach and precision level to gravity sensor	A built in “survey grade” level to gravity sensor is combined with a simple three screw leveling quick release platform for quick and easy machine setup and relocation.
Overview Camera	Integrated Overview Camera to allow on-line steering of the laser tracker for remote or fixed installations
Integrated environmental monitor	Automatic reading and updating of the environmental parameters avoids inaccurate calculations or wrongly input values.
Leica Geosystems proprietary quadruple reading absolute angle detection system	The absolute angle encoders provide traceable ISO 17123-3 0.5” accuracy with a 0.07” resolution guaranteeing system accuracy over extremely long ranges.
Power Over Ethernet	Due to its low power requirements the sensor can use POE+ technology that combines power and data into a single off the shelf Cat5 LAN cable.

Leica Absolute Tracker AT401 accuracy

All accuracies are specified with Leica Geosystems precision 1.5” Red Ring Reflectors and a measurement mode of 2 seconds per point under stable environmental conditions. Full range is specified as 1.5 to 80 meters away from the laser tracker within a vertical range of +/- 45˚.
All accuracies are stated in maximum permissible error (MPE). Typical results are half of MPE.

UXYZ – Full Range
The measurement uncertainty of a coordinate “UXYZ” is defined as the deviation between a measured coordinate and the nominal coordinate of that point. This measurement uncertainty is specified as a function of the distance between the laser tracker and the measured point.
AT401:

+/- 15 µm + 6 µm/m (+/- 0.0006” + 0.00007”/ft)

Dimensions
Sensor Size: 290 x 221 x 188 mm (11.4” x 8.7” x 7.4“)
Sensor Weight: 7.3 kg (16 lbs)
Controller Size: 250 x 112 x 63 mm (9.8” x 4.4” x 2.5”)
Controller Weight: 0.8 kg (1.75 lbs)

Range
Infinite Horizontal Rotation: +/-360˚
Infinite Vertical Rotation: +/- 145˚
Typical working Volume: 320 m

Environmental
Dust/Water: IP54 (IEC 60529)
Operating Temperature: 0˚C to +40˚C
Relative Humidity: Max. 95% (non-condensing)
Altitude: -700 to 5500 m (-2,300 to 18,000 ft)

Motorization
Acceleration: 360˚/s2
Rotation Speed: 180˚/s
PowerLock: 10˚ FOV

Absolute Angular Performance
Resolution: 0.07 arc Seconds
Accuracy (MPE): +/- 15 µm + 6 µm/m (+/- 0.0006” + 0.00007”/ft)
Repeatability (MPE): +/- 7.5 µm + 3 µm/m (+/-0.0003” + 0.00004”/ft)
Inclination Setting Accuracy (2σ): +/- 1 arc second

Absolute Distance Performance
Resolution: 0.1 µm
Accuracy (MPE): +/- 10 µm (+/- 0.00039”)
Repeatability (MPE): +/- 5 µm (+/- 0.0002”)

Laser Emission
Class 2 Laser Product in accordance with the IEC 60825-1
Second Edition (2007-03)

General Information
Overview Camera (OVC)	4:3 IR enhanced Image ≈ 10˚ FOV
Environmental Monitor	Internal – Temperature, Pressure and Humidity External – Air Temperature – Object Temperature
Remote Control	Integrated 4 Button IR
Interfaces	Cable – TCP/IP (Cat5) Wireless – WLAN (IEEE 802.11g)
Power Management	Internal – lithium-ion battery External – AC power supply Optional – Power Over Ethernet (PoE+)