Page 45
Operation
confocalDT 24x1
5.5
Dark Reference
This adjustment must be carried out after every sensor change. Dark referencing is
sensor-dependent and is stored separately in the controller for each sensor. Therefore,
you need to connect the required sensor and select Settings menu > Sensor, before you
start dark referencing.
The controller requires a warm-up time of approx. 30 minutes before capturing dark
signals.
Step-by-Step procedures:
Remove the target from the measuring range, or cover the sensor surface with a
piece of dark paper.
i
For dark referencing, no object must be within the measuring range, and no ambi-
ent or external light must reach the sensor.
On the controller, press the
Dark reference
button
1
, or click the
Start dark
reference
button on the
Dark reference
web page.
The
Intensity
and
Range
LEDs will start flashing, and the sensor captures the current
dark signal for about 20 seconds.
Fig. 30
Dark reference
video signal (example: IFC2451 with LED light source)
After the dark referencing the dark corrected signal is characterized by an almost smooth
waveform directly to the X-axis.
Remove the paper cover from the sensor. The sensor can now be used as nor-
mal.
i
Click
Undo
to reset the previous adjustment. You need to repeat dark referencing
after replacing the lamp in the external light source. And for controller IFC2451,
IFC2461 and IFC2471LED with an internal LED light source you will also need to
carry out dark referencing at regular intervals.
The current brightness value (as the quotient of the sum of all intensities and the current
exposure time), is determined with each new darkness correction. If a major change in
the previously stored value is detected, this can be interpreted as the degree of contami-
nation, and a warning is given.
You can also ignore this message. However, you should note the current exposure
1) After more than 10 seconds, the factory settings will load!
