The first reading of staff at a point or bench mark is called?
The first reading of staff at a point or bench mark is called?
کسی پوائنٹ یا بینچ مارک پر عملے کی پہلی پڑھائی کو کہتے ہیں؟
Explanation
Taken on a known point (like a benchmark).
It’s the starting reading for a new instrument setup.
Used to determine the height of the instrument (H.I.).