Prof. Khaled Mohamed Zaky Hassan :: Publications:

Most of the surveying instruments have changed with the rapid change of technology. One of these instruments is the level. Some leveling works require to be executed in a short time with a high level of accuracy. Also, costs require to be as less as possible. Example of these works is the establishment of bench marks. A part from a road of 2 km length in El Abour City is selected and leveled using an ordinary level, a precise level and a digital level. A comparison has made for the accuracy, time and costs of leveling the center line of the selected road by using these levels. The results of this comparison indicate that the precise and digital levels have gave the accurate work. The difference of accuracy between the ordinary leveling and both of precise and digital leveling reached to 10 mm in a leveling line of 2 km length. The time of digital leveling was shorter than that of the precise leveling and approximately was the same time of the ordinary leveling. At the same time, without counting the price of the levels, the digital leveling is considered more economical than the precise leveling which has took a very long time. Also, the comparison indicates that the digital and precise levels have gave approximately the same accuracy. The closing error of the ordinary leveling was three times the closing error of the precise leveling and four times the digital leveling. The standard deviations of the elevations which obtained from digital leveling were less than their corresponding values which obtained from the ordinary and precise leveling. The adjusted elevations which obtained from ordinary leveling were more than their corresponding values which obtained from precise and digital leveling by about 8 mm at some points. The final result of this comparison is a recommendation to use the digital level for the required accurate leveling.