Some active RFID tags have input and output ports on their circuit boards, enabling users to connect sensors and have sensor data transmitted to readers. There are also a wide variety of active RFID sensors already on the market that can detect temperature, humidity, vibration, acceleration and radiation.
Some passive high-frequency (HF) and ultrahigh-frequency (UHF) tags also have input/output ports that allow you to connect sensors. Most passive RFID sensors on the market are temperature loggers.
—Mark Roberti, Founder and Editor, RFID Journal
What Is the Accuracy of Real-time Location Systems? »