Positioning the Label Sensor for Unique Labels

The information in this document will help you position a moveable sensor to properly sense the gap on standard or uniquely shaped labels to assure consistent calibration.

The printer you have may come with a separate moveable upper and lower sensor (Xi/105SL) or as a combined upper/lower module (ZM-Series, ZT-Series). Most desktop printers have a fixed position sensor so this discussion does not apply.

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Xi/105SL Transmissive Sensor
(Separate upper and lower) and is used for Gap, Notch or holes
The fixed position Black Mark Sensor is
under the print head
ZM/RZ-Series Transmissive Sensor
(Single piece module) Used for Gap Notch or holes.
The Black Mark Sensor is a fixed position module as shown


S4M and ZT200-Series Reflective Sensor
(The S4M/ZT Reflective sensor is adjustable and is used for gap, holes or notches )
S4m and ZT200-Series Transmissive Sensor
S4M and ZT Transmissive Sensor is a fixed position style and is used when the reflective sensor fails to function reliably with a gap label.


The ZM/ZT -Series printers have a red light that helps identify the Moveable Sensor location. For demonstration purposes we'll use this as an example for locating the sensor on the various labels shown. The red light will represent the sensor location for reading the gap. Consult your user guide for information on positioning your printer model's adjustable or moveable gap/hole/notch sensor.

Sensor Positioning Discussion

With the printhead open and the printer power on, locate the Moveable Sensor's red light in the mouth of the printer. The Moveable Sensor can be used for gap, notch, or hole top of form detection.

Align the red light with an area of the label that allows the sensor to view a consistent inter-label gap (2 - 4mm, 3mm recommended). As shown in Figure 1, the sensor is positioned on the jewelry tag at the point it can see the standard 3mm inter-label gap and avoids the wider spacing of the middle of the label. When working with uniquely shaped labels always try to position the sensor so it sees one consistently spaced gap to identify the top of form.

Note: It is recommended that you consider using a black mark on your label backing if positioning the sensor for a single consistent gap is not possible.  


Figure 1. ZM400 Adjustable Sensor positioned to read a consistent 3mm gap
Note: These are jewelry tags without a black mark.


Figure 2 and 3 the sensor position (red dot) for various label types.


Figure 2  Jewelry Tag (without black mark) Figure 3   2 Across Labels

Figure 4 and 5 show the sensor position (red dot) for a notch and a hole.


Figure 4 Notch used for Top of Form

Figure 5 Hole used for Top of Form

While not recommended using the narrowest part of the circle tag (Figure 6) may allow for acceptable gap sensing. It is typical that a black mark is used when using oddly shaped labels.

Figure 6 Circle Label