On a BouMatic Dairy RFID system operating at 139 KHz, how can I limit the noise being generated by a VFD lagoon pump motor that is located 150 yards away? When the VFD is off, the RFID signal is great. When the VFD is on, however, the signal is poor.
To answer your question, I reached out to James Heurich, the president of RFID Inc., a leading RFID solution provider and one of the few that offers passive LF systems. James points out that noise isn't just electromagnetic interference through the air, adding, "It is predominantly over cabling and power lines. If the RFID readers are powered from the same power supply, or share a common ground with the pump, or if the cabling for both share a conduit, noise can be a problem. As for airborne EMI, the best method for testing how to block it is to use a large sheet of metal (household tin foil and cardboard can be used to test where to place the barrier between the motor and the RFID system). I would think Mylar would work. There are also carbon curtains found on Amazon or eBay."
—Mark Roberti, Founder and Editor, RFID Journal