A point upon which B.S and F.S both readings are taken is called?

ایک نقطہ جس پر دونوں ریڈنگ لی جاتی ہیں اسے کہتے ہیں؟

Bench Mark

Change Point

Datum

Double points

Used when shifting the level instrument to a new position.

Ensures continuity in levelling.

Acts as a reference between two setups of the instrument.