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Monitoring arrangement

  • US 4,633,231 A
  • Filed: 02/27/1985
  • Issued: 12/30/1986
  • Est. Priority Date: 02/29/1984
  • Status: Expired due to Fees
First Claim
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1. An apparatus for monitoring the time duration of a person within a given closed region comprising:

  • a portable transmitter assembly to be carried by the person to be monitored for emitting electromagnetic energy and comprising, an energy source, a timing member which, when the transmitter is handed to the person at a first point, is adjusted to a given time duration determined by the normal travel time between said first point and a second point, said timing member being operative, after termination of the adjusted time duration, to energize a transmitter stage to transmit a given information signal, and at least one receiver which, when the transmitted given information signal is received, activates an indication device.

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