ETALON ABSOLUTE MULTILINE TECHNOLOGY

ABSOLUTE MULTILINE TECHNOLOGY combines the strengths of an interferometer and an absolute measuring system to continuously monitor the geometry of machines and structures with the highest accuracy.

The system can precisely measure lengths up to 30 m, with an uncertainty of only 0.5 µm per metre. A single system can operate up to 124 measuring channels simultaneously.

Unlike conventional interferometers, the measuring beam can be interrupted at any time, and in a fraction of a second at the next measurement shot, the system again determines the absolute distance without any loss of accuracy, assuring the highest geometric precision.

Thanks to these unique system properties, this technology takes metrology automation in production to a new level.

The system's exceptional precision and ability to operate in extreme conditions make it ideal for demanding measurement tasks in a wide variety of scientific and manufacturing fields.

Research and development

Position monitoring of mirrors and detectors of large telescopes to reduce set-up times and ensure sharper images
Measurement and positioning of components in a vacuum at particle accelerators, such as CERN
Analysis of the smallest deformations of machines and structures, e.g. for load and temperature tests
Optical surface measurement of deformations and deviations from nominal geometries

Central metrology system, assembly and quality assurance

Automated deformation and position measurements of large structures and components
Factory-wide metrological network for the automated monitoring and compensation of the geometry of machine tools and measuring machines to ensure the dimensional accuracy of manufactured parts
For national metrology institutes, the system serves as a length reference that can be transmitted over long distances to different buildings

A single ABSOLUTE MULTILINE system can drive up to 124 measurement channels. An individual measurement line is highly compact; a single channel comprises a robust glass fibre that can have a length of several kilometres and a small optical collimator, with no electronic components, as the sensor head.

Precise measurement in challenging conditions

Because the distance between the sensors and system electronics can be several kilometres, it is possible to conduct measurements under extremely harsh environmental conditions, far away from the evaluation electronics. The measuring optics and measurement signal are unaffected by electromagnetic or radioactive radiation; therefore, placing sensors in, e.g. energy chains is possible without degradation of performance.

The reference to fundamental physical constants ensures metrological traceability: In every measurement, the molecular absorption spectrum of a gas cell that stays constant over decades is scanned, and the system is thus automatically recalibrated during every measurement.

Features and benefits

Absolute distance measurement from a few millimetres (close range configuration) up to 30 m (standard configuration) and more

Measurement uncertainty (95%) = 0.5 μm/m for distances between 0.02 m and 30 m.

Up to 124 synchronous channels allow for the set-up of complex metrological networks

Robust measurement sensors allow reliable operation in the harshest environments

Measuring fibres up to 7 km in length

Additional channels using sequential multiplexing via fibre switches

Suitable for factory-wide installation with central laser and evaluation unit

Comprehensive software for geometric monitoring in 1D and a server interface for third-party software is available

Technical data

Technical data
Measurement uncertainty	U(95%) = 0.5 ppm
Measurement range	Up to 30 m
Number of channels	4 - 124
Laser class	II m, eye save
Traceability	Calibrated gas spectrum
Compensation	Temperature, pressure, humidity