To accurately discriminate a metal body without any variation in resonance frequency nor the Q value of a coil which is sent form a discriminating body and for activating an RDID circuit even when fitted integrally to the metal body such as a metallic tube.
The RFID element 10 for the metal body is equipped with a magnetic material 11 as a magnetic core, an antenna coil 12 which is wound around the magnetic material, and an RFID circuit 13 which is connected to the antenna coil and the outer circumferential surface of the antenna coil 12 is fitted integrally to the metal body 20 opposite the external surface of the metal body 20 across an electromagnetic shield material 14. The RFID circuit 13 has a memory 13f which stores data characteristic of the metal body 20 and is activated with a radio wave of specific frequency from the metal body discriminating device 30 to read data out of the memory 13f according to a readout command by data communication of the radio wave and write the data to the memory 13 according to a write command, thereby generating a response signal to the discriminating device 30.
YONEZAWA MASA
HACHIMAN SEIRO
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