4VAL Operating & Maintenance Manual Version 1.1 © Newman Labelling Systems Ltd Page 38 of 56
Sensitivity Adjustment
Setting
A two-step set-up procedure is used to set the sensor to the correct sensitivity and
light / dark mode. The sensor output is set to be ON when an overprint is detected.
1) Output ON state acquisition (MARK)
Position the sensor so that the light spot is on the overprint and press the MARK
pushbutton until the green LED turns OFF.
2) Output OFF state acquisition (BKGD)
Move the label so the light spot is now on the background and press the BKGD
pushbutton; the green LED blinks once.
The green LED should now be permanently ON.
If the green LED flashes slowly, the set-up procedure has failed due to insufficient
contrast; repeat the procedure from the beginning.
4.8 PRODUCT SENSOR
The Product sensor is a fibre optic sensor mounted on the machine fitment pad – see
figure below. The fibre optic head is fitted with a focusing lens with 4 mm focal
length and is fixed to an adjustable clamp facing the applicator drum. The lens should
be positioned to achieve a consistent reading from a portion of the container such as
the ‘bulb’ of ampoules.
