METHOD FOR MEASURING TEMPERATURE USING A REMOTE, PASSIVE, CALIBRATED RF/RFID TAG INCLUDING A METHOD FOR CALIBRATION

摘要

A system for tracking environmental parameters, such as temperature, associated with a package during transportation and storage thereof, comprises a passive RFID (Radio Frequency Identification) tag adapted for containment within the package and at least an RFID reader adapted to communicate with such passive RFID tag. The tag includes means for sensing an environmental parameter, such as temperature, means for storing information respecting such parameter, and means for transmitting such information upon activation by such reader. The reader includes means for activating such tag, means for receiving and storing information received from such tag, and means for making such received information available to an interested party. The system may also include a master tag for external association with the package, the master tag prompting the slave tag to transmit data at specific intervals. If the sensed parameter is temperature the slave tag may utilize a tick oscillator, the transmission frequency of which changes in response to temperature changes, the master tag then determining the temperature on the basis of the frequency change.