| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive and simple freshness sensing system, for example, a sensing seal capable of detecting freshness or the like inexpensively and simply, by detecting magnetic field intensity by a magnetic impedance sensor or the like having higher sensitivity by utilizing a magnetic characteristic change of magnetic body powder caused by an environment, in order to solve the problems wherein a sensor, a device and an operation are complicated and require high cost, though freshness sensing is determined hitherto by a color or the like generated by a reaction of an enzyme, a dye, a pigment or the like. SOLUTION: A seal wherein the magnetic body powder whose magnetic characteristic is changed according to a given environment is intermingled or a seal having the powder applied onto the surface part is used as the freshness sensing seal. The magnetic characteristic changing according to an environmental condition wherein a specimen is placed is measured by the magnetic impedance sensor or the like by sticking the seal on the specimen, to thereby recognize the environmental condition. COPYRIGHT: (C)2004,JPO&NCIPI
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