| 摘要 |
In this system, which is suitable, in particular, for monitoring museums, both exhibits and attendants are in each case provided with a transmitter (1, 2) which periodically transmits a standby or alarm signal. The signals of the different exhibits are transmitted consecutively, the time measuring devices (8, 9) controlling this transmission being so highly accurate that they need to be synchronised only once a day. The fixed transmitters (2) are synchronised by portable devices (6) positioned near to the transmitters while the portable transmitters (1) are synchronised by stationary devices (5). <IMAGE>
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