PRIMES
BeamMonitor BM+ with LDS 2.98
36
Revision 01/2018 EN
With this dialogue window either single measurements or repeated measurements can be carried out.
The measuring mode Monitor starts a continuously repeating measurement with current settings. The repeti-
tion rate is dependant on the spatial resolution as well as the rpm. With 64 x 64 pixels the measuring time
is about 10 seconds.
The monitor operation can be terminated by clicking the button
Cancel
in the status window (in the bottom
right corner of the screen).
Fig. 11.5: Status window
The measuring window position can be set either manually or automatically.
With the button
FindBeam
the measuring window of the BeamMonitor BM+ is set automatically. In this case,
the system only searches in the range given in the currently set window in the set z-position. Afterwards the
window
FindBeam
appears.
In case the beam search is completed successfully, a measurement window with the found beam in the
measuring field of the single measurement window appears. However, at that point the window size is not
yet optimized. With the button
Start
the beam can then be recorded.
As far as the manual beam search is concerned the position as well as the size of the measuring window
within the mechanical limits can be stipulated by the operator. The choices can be made in a pop-up menu,
where [x] for square measuring windows or respectively [x] and [y] for rectangular are to be stipulated. The
maximum size of the measuring windows is - in case of the BeamMonitor BM+ – in the standard configura-
tion 8 mm x 8 mm (optional up to 24 mm x 12 mm).
The position of the measuring window is changed by clicking on the frame and moving it by means of the
mouse. The position of the window in z-direction (height) can be stipulated by means of the z-slide control or
by means of a numerical entry. The zoom function enables a detail enlargement in the measuring window.
Size of the measuring window
In order to minimize the measurement errors, we recommend a measuring window size which ensures that
the beam diameter equals 30 % to 70 % of the base side length of the measuring window. The distribution
has to be preserved at full extent without a restriction by the border of the measuring window.
Electrical amplification
The power density distribution is measured by a detector. Its analogue output signal is amplified and then
digitalized. There are different detectors available (see Tab. 15.1 on page 69)
In case the detector oversaturated (red LED symbol in the display for the signal saturation or – respectively
– a ADC value of 4095 in the presentation
Variable Contour Lines
), please reduce the amplification
by means of the slide control “ampl.” and repeat the measurement.
Not only an oversaturation but also a low amplification lead to unsecured or false results. We recommend
the readjustment of the amplification in order to receive correct results.
Laser power
The laser power can not only be set by means of the slide control but by entering it numerically. The reference
value for the laser power is entered in the dialogue window
Measurement>>Environment
. The calculation
of power densities refers to the power values set here.
Please click on the button
Start
to start the measurement.
Up to 50 single measurement planes can be part of one measuring file. This is relevant for measurements
of the beam caustic as well as for time or power series. It is possible to switch for presentation between the
individual measuring planes.
