This video shows a simple example of how to determine elevations with an optical level and the Android app GNU-Nivellus. First, you need to enter the foresight, backsight and the height of the benchmark in order to calculate the elevation of a new point (NP). By specifying a second benchmark with a known altitude, the measurement can be checked and the amount of measurement error (misclosure) can be determined. This is then distributed over the backsights (adjustment). Further one can determine the allowable misclosure on the basis of a formula, in which a constant and the length of the measuring section are included.
At the end, other functions that the app has to offer are presented, such as sharing, file formats, display, language settings, and more.
Further information: www.level-online.net/gnu-nivellus/index.php?lang=en