Spatial temperature profiling by semi-passive RFID loggers for . - UPM
RFID tags can be active, passive, or semi-passive. Passive and semi-passive RFID send their data by reflection or mod ulation of the electromagnetic field that was emitted by the Reader. The typical reading range is between 10cm and 3m. The battery of semi-passive RFID is only used to power the sensor and recording logic.