4-6
4 Measuring
Stand-off
distance
The stand-off distance is measured from the front of the scanning head (refer
to the following figure).
Figure 4.2: Measuring the stand-off distance
4.3.2 Optimal Stand-Off Distances
The relation between stand-off distance and signal level is shown in the
following figure. The optimal stand-off distances are marked as visibility
maximum.
Figure 4.3: Relation between stand-off distance and signal level
SIGNAL
LASER
Polytec
PSV-500
SCANNING HEAD
Stand-off distance
Object
Laser beam
Signal level
Stand-off distance in mm
Visibility maximum
Visibility minimum
Two laser modes with equal intensity
Two laser modes with different intensity
A strongly dominant laser mode
141
345
549
... + 204
OPTION