Sensor tag
Specialty tags
What is it?
Sensor tags combine an RFID transponder with one or more environmental sensors – temperature, humidity, light, pressure, tilt, or shock. They can be passive (powered by the reader's RF energy at the moment of interrogation) or battery-assisted (logging data continuously and transmitting on demand). Sensor tags are enabling cold chain monitoring, condition-based maintenance, and environmental compliance without wired infrastructure.
How it works
Passive sensor tags use the energy harvested from the reader's RF field to power a sensor measurement at the moment of reading. The sensor value is stored in the tag's memory or modulated directly into the backscatter response. Battery-assisted passive (BAP) tags include a small battery that powers continuous logging – the tag records temperature (or other parameters) at set intervals and stores readings in memory, which is downloaded when a reader interrogates the tag.
Use cases
- Cold chain monitoring (pharmaceuticals, food)
- Blood and vaccine temperature logging
- Equipment vibration and shock monitoring
- Humidity monitoring for art and museum storage
- Data centre environmental monitoring
- Perishable goods logistics
Pros
- Environmental monitoring without wired infrastructure
- Passive versions require no battery
- Combines identification and sensing in one device
- Can provide evidence of storage condition violations
- NFC sensor tags can be read with a smartphone
Cons
- Higher cost than standard RFID tags ($5–$50+)
- Battery-assisted versions have limited battery life
- Sensor accuracy lower than dedicated instruments
- Passive sensors only measure at the moment of reading
- Data logging capacity limited by tag memory
Specifications
| Power type | Battery-assisted passive (BAP) |
|---|---|
| Frequency | UHF (860–960 MHz) or HF/NFC (13.56 MHz) |
| Read range | UHF: 1–8 m; NFC: tap |
| Lifespan | 1–10 years (battery-assisted versions: 2–5 years) |
| Price range | $5–$50+ per unit |
| Environmental rating | Varies by model; some IP67 rated |