Abstract: A system for returning residual liquid remaining in a loading line to a liquid cargo container after loading or unloading of the cargo container. This system includes a liquid return line extending between the loading line and the cargo container. A pump is positioned to move liquid from the loading line, through the liquid return line, and into the cargo container. A vapor line communicates between a vapor space in the cargo container and the loading line. The system may include an optical liquid level sensor. The level sensor includes a light tube having two substantially straight sections joined by a substantially continuous curvature bend. The bend has a rounded cross-section and the light pipe is formed of a light conducting material. An optical emitter is positioned at the end of one of the straight sections of the pipe and an optical detector is positioned at the other straight section of the pipe. A micro-controller activates the optical emitter and monitors the optical sensor.

Abstract: A livestock identification apparatus 10 for automatically identifying and sorting livestock as they walk through the apparatus 10 is disclosed. The apparatus 10 includes an alley 12, a gate 14 for controlling passage through the alley 12, and an identification sensor 18 disposed within or adjacent the alley 12 for identifying animals passing through the alley 12. The identification sensor 18 includes a pair of rigid antennas 48,50 positioned on opposite sides of the alley 12 for energizing and reading transponders on animals passing through the alley 12. In another embodiment of the invention, the identification sensor 208 includes a gate 204 controlling entry into a milking parlor or other confined area, a first stationary antenna 210 positioned on one side of the entrance to the milking parlor and a second moveable antenna 212 integrally formed with the gate 204.