An RFID sensing system includes a passive RFID sensor, a reader capable of collecting temperature from the sensor and its antenna. The reader’s antenna constantly sends radio frequencies signal to the sensor. On one hand, the radio frequency transmits energy to activate the sensor. While simultaneously transmitting a command including the sensor’s ID, telling it to measure the temperature. After activation, the sensor sends the current temperature back to the reader. The whole process is a digital transmission with CRC code under RFID’s ISO Protocol, making it stable and reliant.