Polytec PSV-500, Hardware Manual

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6-3
6 Fault Diagnosis
6.2.2 Highly Fluctuating Signal Level Display
If the signal level display on the back of the scanning head or in the software
periodically fluctuates greatly, proceed as follows:
1. If your system is equipped with the optional PSV-A-560
CoherenceOptimizer, wait until the status of the CoherenceOptimizer
state is shown as being stable in the software. Refer also to your software
manual on this.
The CoherenceOptimizer stabilizes the laser and the fluctuation of the
signal level display stops.
2. Check if your object is positioned in a visibility minimum of the laser.
If so, change the distance between the scanning head and the object.
You will find detailed information on optimal stand-off distances and
visibility maxima in
SECTION
4.3.
6.3 No Measurement Signal or Implausible Measurement Signals
If the laser beam is emitted, but there is no measurement signal or just
implausible measurement signals, check the following:
1. Have you connected up the system correctly as described in
SECTION
3.5 ?
2. Put a matt white test surface such as a piece of paper approximately
50 cm away from the front panel of the scanning head in the beam path
and focus the laser. Does the signal level display light up ?
If the signal level display does not light up, the scanning head is
defective.
Data acquisition Check the correct operation of the data acquisition and the software. To do
so, proceed as follows:
1. Connect up the signal output of a function generator to the REF 1
reference channel.
2. Display the time signal of the reference channel in an analyzer as
described in your software manual.
The data acquisition and the software work properly if the signal of the
function generator is displayed correctly. In this case there is a problem
in the front-end.