Positioning the ZT400 Gap 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 ZT400 Series come with a moveable Transmissive Sensor for detecting label gaps, tag notches or holes and a Reflective Sensor for Black Mark detection.

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ZT400-Series Transmissive Sensor
This Transmissive Sensor is adjustable and is used for
gap, holes or notch detection 

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ZT400-Series Reflective Sensor
ZT Reflective Sensor is a fixed position style and
is used for Black Mark Media


The ZT400 printer's Transmissive Sensor has a red light that helps identify the sensor's location relative to the media. We'll show examples for locating the sensor on the various labels shown. The red dot in the pictures will represent the sensor location for reading the gap.

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