Title: Establishing an invar leveling calibration system
Authors: Chen, Chun-Sung
Wu, Chien-Ting
Chang, Ming-Wei
Chang, Wei-Chen
Department of Civil Engineering
Keywords: invar leveling rods;calibration system
Issue Date: 1-Jul-2008
Abstract: Precise height systems are widely utilized in civil engineering projects Such as high-speed railroads, and highways and bridge construction. However, highly precise height data is obtained using precise leveling. An extremely precise invar leveling rod is necessary for obtaining precise results. In this study, an automatic calibration system for invar leveling has been established by the National Measurement Laboratory (NML). The content belongs to the long scales calibration system of D17 of the NML. This system utilizes a steady frequency laser interferometer, a CCD microscopic monitor, and a precise moving mechanism. With this system, an invar rod and a mark invar leveling rod are applied to estimate uncertainty with a 95% confidence level. Uncertainty results are 22 mu m and 21 mu m for the invar leveling rods and mark invar leveling rods, respectively.
URI: http://hdl.handle.net/11536/8639
ISSN: 0253-3839
Volume: 31
Issue: 5
Begin Page: 861
End Page: 866
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