If RL of BM is 240.00 m and reading on staff is 2.024, then the H.I. will be…? (CG RHEO 2017)

✅Explanation:
In surveying,
-RL of BM (Reduced Level of Bench Mark): A benchmark is a point of known elevation. RL of BM is the elevation of this benchmark above a reference datum (usually mean sea level).
-Staff Reading: The reading observed on a levelling staff when it is held vertically on a point whose elevation is to be determined.
-H.I. (Height of Instrument): The elevation of the line of sight of the leveling instrument.

• The Height of Instrument (H.I.) is calculated as:
H.I. = RL of BM + Staff Reading

• Therefore, in this case:
H.I. = 240.00 m + 2.024 m = 242.024 m