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3. READ RANGE MEASUREMENTS

Read range measurements were carried out using a ThingMagic reader unit (Mercury 2, version 1.2.9
software) and a linearly polarised reader antenna. The read range measurement set up is shown in
Figure 5. When the maximum read range was measured, the criteria for reliable identification was that
the reader continuously identified the tag for at least one minute at the maximum reading distance. To
study the effect of the aluminium foil on the read range, the measurements were carried out using
packs with the foils, packs without foils and an empty carton.

Tagged carton or cartons
Figure 5: The read range measurement setup

3.1 Read Range Measurements of One Carton and Comparison to the Measurements with a
Conventional Tag

Read range measurements were carried out with two individual integrated patch-type tags and two
conventional folded dipole-type tags. The read ranges are an average value of the read ranges
achieved with the two individual tags. The folded dipole-type tag is presented in Figure 6.

Figure 6: Folded dipole-type tag

Table 1 shows a comparison of the read ranges achieved with both tag types. It can be observed that
when the aluminium foil is not removed from the packs the carton cannot be identified when folded
dipole tag is used. However, with the integrated patch-type tag a read range of 1.05 m is achieved.
When the foils are removed from the packs, the read range of the integrated patch-type tag almost
doubles. The read range of an empty carton is only slightly longer than the read range of a carton with
packs without the foils. When the foils are removed from the packs or an empty carton is measured,
typical read ranges of over 2 m are achieved with the folded dipole tag.

TABLE 1
COMPARISON OF MAXIMUM RF.AD RANGES OF THE TWO TAG TYPES

Tag antenna Packs with Packs without Empty carton
foils foils
Integrated patch
1.05 m 1.95 m 2.00 m
Folded dipole 0m 2.40 m 2.75 m