Measuring system for straightness and parallelism error of the overlong target vehicle guides

To measure the straightness and parallelism error of high precise and the overlong guides (or so 1500m) is different to measure the common guides. We apply principle of the optical collimation to measure the straightness error of the subsection guide in turn from the one end with laser collimation instrument. This way calls separate method. After measuring the straightness error of one of the datum guides, we measure the parallelism error of the guides. This way calls objective method. We can assess the straightness and parallelism error by adopting illustrate or numeration to compile procedure to deal with data and draw the curve of error.