Thermotag

Abstract

Temperature sensing plays a significant role in upholding quality assurance and meeting regulatory compliance in a wide variety of applications, such as fire safety and cold chain monitoring. However, existing temperature measurement devices are bulky, cost-prohibitive, or battery-powered, making item-level sensing and intelligence costly. In this paper, we present a novel tag-based thermometer called Thermotag, which uses a common passive RFID tag to sense the temperature with competitive advantages of being low-cost, batteryfree, and robust to environmental conditions. The basic idea of Thermotag is that the resistance of a semiconductor diode in a tag's chip is temperature-sensitive. By measuring the discharging period through the reverse-polarized diode, we can estimate the temperature indirectly. We propose a standardscompliant measurement scheme of the discharging period by using a tag's volatile memory and build a mapping model between the discharging period and temperature for accurate and reliable temperature sensing. We implement Thermotag using a commercial off-the-shelf RFID system, with no need for any firmware or hardware modifications. Extensive experiments show that the temperature measurement has a large span ranging from 0 • C to 85 • C and a mean error of 2.7 • C.

Body Temperature Related Risk Factor Assessment Using RFID Sensor Tags

“…The sensor tags used in the paper are energized from the energy relays that harvest energy from electric fields inside the substation; therefore, the energy source is unlimited, and measurements can be taken long-term. In the work presented by Chen and friends, a temperature measurement is performed using a resistor temperature-dependent value on an off-the-shelf RFID Tag [9]. The authors claim that the temperature measurement range with their approach is 0 C to 85 C with an accuracy of 2.7 C. Catarinucci et.…”