| 摘要 |
A device is proposed which is used, in particular, for monitoring objects. The principle of a radio system, known per se, is modified in such a manner that an object to be monitored is provided with a transmitter sending out a transmit signal. A receiver adapted for the transmit frequency of the transmitter receives the transmit signal. The sensitivity or a reception threshold of the receiver can be set in such a manner that when a certain distance between the transmitter and the receiver is exceeded, an alarm signal is output at the receiver.
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