| 摘要 |
A railway surveying apparatus is disclosed. The apparatus has a light beam transmitter for transmitting a beam along the track, a light beam receiver and an intermediate shadow board all mounted on respective rail-engaging buggies so that the transmitter, receiver and board are located on the center line of the track. The shadow board and receiver buggies are connected through a twist transducer that measures the relative angular positions of the buggies. A pendulum is mounted on the receiver buggy and serves to measure the actual rail cross level condition at that point. A pendulum on the transmitter buggy and appropriate circuitry can reference the apparatus to either the track center line or one of the rails. |
