Issue / Question
How do you adjust the GT800's movable sensor for black marks or notches?
Resolution / Answer
The black mark sensor looks for non-reflective surfaces such as black marks, black lines, notches or holes in the media which do not reflect the sensor’s beam back to the sensor’s detector. The sensor light and it’s black mark detector are next to each other under the sensor cover (dark plastic cover is translucent to the sensor’s non-visible light).
Aligning the movable sensor’s alignment arrow to the middle of the black mark or notch in the underside of the media. Sensor alignment should be set as far as possible from the edge of media but where 100% of the sensor window is covered by the mark. When printing, the media can move from side to side ±1mm (due to media variations and edge damage due to handling). Notches cut into the side of the media can also become damaged.
Load the media. Before closing the printer, adjust the movable black mark sensor as follows:
1. Flip the media back over the roll to expose the black marks or notches on the backside (non printing side) of the media.
2. Slide the movable sensor from the center default position to align with the black marks.
The arrow on the movable sensor should line up with the center of the black mark. This is true for marks or notches located on either side of the media (left side shown).