NCEES Fundamentals of Surveying (FS) Practice Exam

The primary purpose of a tachymeter in surveying is to measure horizontal distances and angles simultaneously. This fast and efficient instrument combines the functionalities of both a theodolite and a rangefinder, allowing surveyors to gather distance and angle measurements in a single setup. By doing so, tachymeters facilitate quick data collection, which is essential for various surveying tasks such as establishing control points or mapping areas.

This dual measurement capability is particularly useful in many surveying applications, including construction site assessments, topographic surveys, and road design. The simultaneous measurement helps to increase productivity, as it reduces the need for multiple setups and calculations.

In contrast, while detailed topographic maps can be created using tachymeter data, the primary function of the instrument is not focused solely on mapping but rather on simultaneous distance and angle measurement. Measuring vertical angles exclusively and providing elevation data only are specific functions but do not encompass the overall primary function of a tachymeter.