Flow monitoring devices

A liquid flow indicating device for sensing intermittent liquid flow and adapted for mounting on a sample-collecting container and comprising a flow monitor mounted on top of the container, the flow monitor having means forming a chamber having an inlet for the entrance of liquid and an outlet spaced from said inlet for the flow of said liquid out of said chamber, said liquid flowing along a path defined at its beginning by said inlet and at its end by said outlet, a probe mounted intermediately along the path in said chamber and comprising an energy transmitter and an energy receiver in spaced apart relation within said chamber, said transmitter being disposed on the transversely opposite side of the liquid path from said receiver said transmitter and said receiver having a passageway therebetween which includes said path and which permits the flow of said liquid along said path and between said transmitter and said receiver, whereby the flow of liquid along said path alters the energy transmitted across the path from said transmitter to said receiver, and the outlet receiving the liquid from the chamber and communicating with the container to deliver the liquid to the container and drain the chamber when no liquid is delivered to the inlet, a signal being generated when liquid is in the chamber between the transmitter and the receiver to indicate the intermittent flow of liquid through the chamber and the filling of the container.