Abstract: A method and apparatus for indicating the presence of one or more trains near a railroad crossing having at least two train tracks. The signaling system has a first sensor for detecting the presence of the first train near or approaching the railroad crossing and a second sensor for detecting the presence of the second train near or approaching the railroad crossing. A warning signal having a first and second mode is responsive to the sensors such that the detection of either the first train or the second train generates the first mode warning signal and the detection of both the first train and the second train generates the second mode warning signal.

Abstract: A method of coding a high-speed object having a lateral travel path with a multi-digit production series number is disclosed. A first marking member and a second marking member are provided, with the second marking member positioned vertically adjacent the first marking member. A plurality of marking locations are defined and a group of marks are applied along each of the plurality of marking locations. The quantity of marks in each group represents a respective digit of the multi-digit series number.

Abstract: A method for determining the level of a first layer of liquified material submerged below a second layer of liquified material is disclosed. A tube having first and second opposing tube ends includes a sacrificial cap covering the first tube end. The tube is adapted for insertion of the first tube end through the second layer into the first layer. The cap is adapted to substantially disintegrate after insertion into the first layer, such that pressure pushes a portion of the first material into the tube to a level substantially equal to the level of the first layer. A sensor determines the level of the measured portion in the tube.