How Can I Read Dish Tags on a Table?

We have a table with a working area of 400 millimeters by 180 millimeters (15.75 inches by 7 inches). In this area, we put plastic dishes whose dimension are 35 millimeters by 5 millimeters (1.4 inches by 0.2 inch). I can't put dishes on an RFID reader, however, as the table is temperature-controlled and the dishes need that temperature. We tried looking for tags 5 millimeters (0.2 inch) in height, but they are not available. Now, suppose I placed an RFID reader on the long side (400 millimeters) and stuck tags at the bottom of the dish. Would the reader read the tags when I placed them on the table?

—Sanjay

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Sanjay,

If I understand your situation correctly, the dishes are 5 millimeters high, and the tags will need to go on the bottom of each dish because there are no tags that would fit the dish's small height. You would not be able to put a reader directly beneath the dishes, due to temperature controls, so the reader would need to be positioned next to the work space, at the 400-millimeter length.

You would need a reader positioned beside your workspace that can read tags on the bottom of your dishes. That would be tricky from that orientation, however. RFID Inc. sells a UHF RFID tag that measures 22 millimeters by 8 millimeters (0.9 inch by 0.3 inch), but effectiveness would drop based on orientation. The company's president, James Heurich, suggests using a mat-style antenna; placing an antenna 8 inches above the table would enable reading of that size tag. The number of plates being read at a time could affect results as well.

Claire Swedberg
Senior Editor
RFID Journal