A sensor system comprises a tag. The tag comprises at least one sensor, a radio-frequency chip, and a first antenna. The sensor is adapted to provide an output analogous to a change in an environment of the sensor. The sensor produces an analog output and includes output terminals. The radio-frequency chip comprises a memory element, input terminals and output terminals. The input terminals are disposed in electrical communication with the output terminals of the sensor. The output of the sensor alters the value of at least one bit in the memory of the chip. The first antenna is disposed in electrical communication with the output terminals of the chip.
