NICET - Highway Construction Inspection Practice Exam

What formula helps to find the turning point elevation?

1. HI = BM + BS

2. TP = HI - FS

3. ΣBS - ΣFS = ΣLast RL - ΣFirst RL

4. TP = FS + HI

The correct answer is: TP = HI - FS

The turning point elevation is determined using a formula that considers both the height of instrument setup and the foresight measurement. The chosen formula states that the turning point elevation is calculated by subtracting the foresight from the height of the instrument (HI). This is essential in surveying and highway construction because the turning point serves as a reference elevation where the surveyor changes the level instrument’s position, and accurate measurements are critical for ensuring proper grading and alignment in construction processes. By using the formula, the surveyor can ascertain the elevation at which the instrument was aimed before it was moved, allowing for a smooth transition of leveling and ensuring precision in the overall construction project. Other formulas listed refer to different relationships in surveying. For example, the first option relates to establishing a bench mark and backsight measurement, while the third describes an elevation difference between survey points. The fourth mentions adding foresight to the height of the instrument, which may not be applicable for finding turning point elevation.