Transponder

A transponder includes a receiving and evaluating section (22) and a transmitting section (28). It further includes an energy storage means (18) which is chargeable by an HF interrogation pulse furnished by an interrogation device and supplies the supply voltage for the receiving and evaluating section (22) and for the transmitting section (28). An identification generator (30) in the transponder furnishes identification data fixedly associated therewith and a measurement data generator (32) receives from a sensor (34) measurement signals and converts said measurement signals to measurement data. The receiving and evaluating section (22) clears the transmitting section (28) for transmitting the identification data only when the supply voltage exceeds a first predetermined threshold value. The transmitting section is cleared for transmission of the measurement data only when the supply voltage at the energy storage means (18) is greater than a second predetermind threshold value which lies above the first predetermined threshold value.