Condition monitoring of engineering structures / SHM with

S-Type Laser System

We use laser distance sensors for permanent bridge monitoring. The measured variable is the restoring or load behavior of the structure.


The measurement system for condition monitoring of bridges records and monitors the load behavior of the supporting structure. The measuring principle is dynamic deformation measurement between two measuring points over a distance of 1 to 100 meters. The displacements are measured with a resolution in the tenth of a millimeter range.


In addition to condition monitoring of bridges, the laser system is also suitable for geometric monitoring of hydraulic structures and production plants.


Laser measuring track



  • Range 1 ... 100m
  • Accuracy < +/-0.5 mm over entire measuring range
  • No aging of the measuring sections
  • Temperature compensation by reference measuring section


 A laser measurement section consists of an active laser distance sensor and a passive measurement target. The lasers are mounted at a fixed point such as the abutment, and the measurement targets are typically mounted halfway across the span of the superstructure.




Measuring principle




  • Vertical displacements at the measuring point are detected via horizontal distance measurements with an accuracy of < +/- 0.5 mm.



The measuring sections do not contain any moving parts. The measuring sections are non-aging and designed for a service life of more than ten years. The dynamic behavior of the structure is recorded permanently and with high precision at the measuring points, and external influences are recognized as such and compensated for.




Measurement setup at a 2-span prestressed concrete bridge



  • 4 Laser-mesuring lines
  • 1 Refernce measuring line
  • 4 Tempeartue measuring points



       1 ... 4  Measuring targets

       M        Laser distance sensors



Via changes in the resetting behavior, fractures of tensioning elements can be detected before cracks become visible on the surface.


The S-type series is a modular measurement system for structural monitoring (SHM) of engineering structures. The measured variable is the dynamic deformation behavior of the structure, which is permanently recorded with fixed laser measuring sections.



Data Sheet - S-Type Laser System


Measuring Line



1 … 100m

Samplimg rate

20 Hz

Typical repeatability

± 0.5mm over entire measuring range


0.1 mm

Laser class

Laser class  2 visible λ = 650 nm

Protection class


Operating temperature

-20 … +60°C 


RS422- 24 bit – gray encoded




Power supply

230V AC / 12V DC


8 digital (laser)  - 4 analog (temperature)

Protection class


Operating Temperature

-20 … +60°C



Operating system



- Data output CSV files with time stamp


- Ring buffer for 3 month


- Alarm in case of limit value exceeded



Datenblatt Lasermessstrecke


Datenblatt DLM 21.1.8 - Laserbasiertes Monitoringsystem für Ingenieurbauwerke
Datenblatt DLM 21.1.8 stationär.pdf
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