| 摘要 |
PROBLEM TO BE SOLVED: To accurately identify a metal body such as a metal pipe without varying a resonance frequency, which is sent from the identifying device and activates a radio frequency identification (RDID) circuit and the Q-value of a coil, even when the device is integrally fitted to the metal body. SOLUTION: An RFID element 10 for a metal body is equipped with a magnetic material 11 such as a magnetic core, an antenna coil 12 wound around the magnetic material, and a RFID circuit 13 connected to the antenna coil. The outer peripheral surface of the antenna coil 12 is fitted integrally to the metal body 20 facing opposite the external surface of the metal body 20 across an electromagnetic shielding material 14. Thge RFID circuit 13 has a memory 13f storing data characteristic of the metal body and is activated with a radio wave of specific frequency from the identifying device 30 for the metal body to read the data out of the memory 13f with a readout command communicated with a radio wave and also write data to the memory 13f with a write command, thereby generating a response signal with respect to the identifying device 30. |
