Have you ever come across a device that can sense if liquid is being sent through a hose, and then send this information, along with an ID, via radio frequency identification?
I am unaware of any off-the-shelf RFID system designed for this purpose, but it is likely that a low-frequency (LF) solution would work for your purposes, provided that the hose’s diameter was not too large and that the hose was not composed of a material that reflects energy from a reader. LF tags work well in the presence of water and other liquids, and their read range is relatively short (less than 3 feet). You should be able to put passive LF transponders encased in glass into the liquid pumped through the tube, and thereby read each transponder’s ID number as it passes the reader antenna.
Biologists with the U.S. Department of Commerce’s National Oceanic and Atmospheric Administration (NOAA) have been using passive low-frequency (LF) tags to count rockfish in the waters off the coast of Washington State (see Fishing for Information). The glass-enclosed tags are inserted into the fish and are then identified as they swim past a reader antenna. The same system should work for your needs.
—Mark Roberti, Founder and Editor, RFID Journal
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