CST Level 1 Land Surveyor Certification Practice

Which instrument is primarily used to measure angles in vertical and horizontal planes?

1. Total Station

2. EDM

3. Theodolite

4. Surveying Level

The correct answer is: Theodolite

The theodolite is specifically designed for measuring angles in both vertical and horizontal planes, making it the primary instrument for this function in land surveying. It consists of a rotating telescope mounted on a base, allowing surveyors to accurately measure angles to a high degree of precision. The theodolite can measure horizontal angles between two points, as well as vertical angles, which are essential for various surveying tasks, such as determining the slope of a landform or establishing control points in construction. In contrast, while a total station includes the functions of a theodolite and can measure angles, it is primarily a more advanced tool that integrates electronic distance measurement (EDM) capabilities. This means that while it also measures angles, its primary feature includes distance measurement. EDM itself focuses on measuring distances using electromagnetic waves and doesn't have the capability to measure angles directly. A surveying level is designed for measuring height differences and establishing horizontal planes, but does not measure angles at all. Thus, the theodolite accurately holds the position of the instrument specifically intended for measuring angles in both planes.