Abstract: A method for identifying a fluid interface in a conduit through which at least a first fluid and a second fluid are configured to pass, includes transmitting, via an ultrasonic flow meter coupled to the conduit, an acoustic signal into the conduit. A reflected acoustic signal is received in the ultrasonic flow meter and the amplitude of the reflected acoustic signal is determined. The average and standard deviation of the amplitude are calculated and, if the standard deviation exceeds a predetermined threshold, the fluid interface is identified as being present in the conduit.

Abstract: A modular rail fence construction adapted for easy erection and removal characterized by rails of predetermined standard length, posts that comprise a shell surrounding and supported by a metal pipe driven into the ground, the post shells being assembled, on site if desired, to provide posts of the various types required, and connecting devices for joining the rails and posts that allow relative angular movement therebetween.