Response unit transmits at least one radio signal in reply to activation signal and incorporates active transmitter whose capacity is greater than that of response signal, together with feed device for feeding transmitter

摘要

The response unit (8) transmits at least one radio signal in reply to an activation signal and incorporates an active transmitter (12) whose capacity is greater than that of the response signal, together with a feed device (14) in the form of a battery for feeding the transmitter. The response unit can be placed in a connecting manhole (2) of preferably a telecommunication network or of a network for distribution of water or gas. The response unit incorporates at least one rod-shaped antenna (10) and has devices for positioning it with the antenna as high as possible in the connecting manhole. The detection response unit is normally in a rest state and on receipt of an activation signal changes from that state to one of vigilance.