The BeamControlSystem (BCS) enables the automatic measurement of the most important laser beam parameters within industrial laser processing lines. Beam power, as well as focal measurements and power density distributions are measured by the system which is shielded, rendering it completely dust-proof.
In the field
In robot cells for laser beam welding this BCS is mounted in a reference point, for example. Each time the robot or Cartesian axes are referenced, a laser beam analysis can be initiated. The entry aperture of the BCS is opened by the robotic or master controller and a measurement cycle is started.
If the EVALUATION function is used, min-max values for focus dimensions, laser beam power etc. will have been specified, so that alarm signals can be initiated as soon as these tolerances are exceeded.
Manual evaluations allow the recording of measurement data and generation of trends. Very often focal position, focal dimension, diffraction index M2 or beam parameter product change subtly over time. This means, for example, that the heat-affected zone of a laser beam welding process could slowly but steadily expand. The thermal lag of the manufactured components would thereby increase just as steadily, and perhaps even without being noticed.
Characteristics of the BeamControlSystem
- Focal measurement from 0.2 mm to 3 mm
- SPS interface for communications with laser or plant controllers
- Script-controlled automatic measuring sequences
- Monitoring of thresholds for beam parameters
- Electro-pneumatic closing device
- Control and measurement data management via PC
- Fieldbus interface optional for system integration
Measurement methods – the principle
This combination device combines the functionality of two different PRIMES products into one compact measuring device. This makes the combination device ideal for permanent integration into a laser material processing plant.
Both systems communicate with a higher level controller, preferably using the script control within the PRIMES LaserDiagnoseSoftware. This enables the fully automated measurement of power and focal geometry initiated by the laser or plant controller.
The EVALUATION function allows measurement data with specified thresholds to be compared and the appropriate alarm signals to be sent back to the laser or plant controller. Overall, this enables the completely automated monitoring of the beam parameters. The combination device is enclosed and completely dust-proof. The beam entry is sealed in stand-by mode by a pneumatic closing device. This allows the measuring devices to work over the long term in a harsh industrial environment.
Measured beam parameters
In order to achieve additional certainties in the context of quality assurance, the essential laser beam parameters are monitored.
- Beam power, typ. ± 3%
- Focal position z, up to typ. 10% zR
- Focus diameter, typ. ± 5%
- Rayleigh length, typ. ± 5%
- Beam parameter product, typ. ± 10%
- M2, typ. ± 10%
- Ellipticity, typ. ± 10%
- Astigmatism, typ. ± 10%
- Beam direction z, typ. ± 0.2 °
Models and options
CPM F-1 (1 kW)
The CPM F-1 is a calorimetric power meter for the range of 100 W to 1.4 kW based on the CompactPowerMonitor CPM F-10. The format was significantly reduced in order to enable it to work in very confined laser processing cells.
CPM F-10 (10kW)
Attention is drawn to the CPM F-10, which is distinguished by its large flat absorber and its low weight, as well as the extremely low back reflection. The calorimetric measurement principle allows high-precision measurements independent of the beam diameter and the strike position on the absorber.
CPM F-20 (20kW)
Its "big brother" has also been optimised in weight. The clear aperture of 135mm allows power measurement far behind the focal plane or also of very large raw beam diameters, e.g. behind a telescope.
For significantly higher power densities, the CPM C-9 with a conical reflector and cylindrical absorber is used. The allowable intensity is up to 10 kW/cm². All models are water-cooled and designed for long-term use – also with deionised water.
- Adapter for measurement at the fibre (LLK-B, LLK-D, QBH, QD)
- Safety, transport and storage cases
- External display unit
- Various interfaces
- Fastening accessories for mounting on the FocusMonitor
The fibre adapter serves to directly couple a fibre to the power meter. This means that laser power measurements are possible even on high power lasers under safe conditions.
Adapters are available for CompactPowerMonitors CPM F-1, CPM F-10, CPM F-20 for a number of common fibre connectors, such as LLK-B and LLK-D and also QBH and QD.