Abstract: A passive device for detecting fluid flow in a pipe includes a housing, a mechanical couple for attaching the housing to at least one of the pipe and a structure disposed in close proximity to the pipe, and a chamber disposed within the housing such that the chamber is physically isolated from the pipe. The chamber is sized and shaped to receive a sound wave at a first end thereof and to amplify the sound wave between the first end and a second end of the chamber, the sound wave including a frequency range corresponding to that of a predetermined fluid flowing through an interior of the pipe. A sensor disposed at the second end of the chamber receives the sound wave amplified by the chamber, and communications circuitry is configured to send a signal corresponding to the sound wave received by the sensor to an external computing device.

Abstract: A call forwarding device includes a plurality of selectively interconnectable channel switches, each having a rotary port connected to a different outlet port of a telephone rotary switch and a modem port connected with a different modem of a facility answering site. An inbound call on any channel switch rotary port is initially directed to the modem port of the same channel switch for answer by the connected modem. If this modem fails to timely answer, the call is automatically re-routed internally of the answering site to the modem port of another, available channel switch for answer by its connected modem or is automatically re-routed to the rotary port of another, available channel switch and call forwarded externally to a backup answering site for answer by a modem thereat.