LEVEL STAFF AND ITS TYPES
Levelling Staff :
The
levelling staff is a rectangular rod having graduations.
The
staff is provided with a metal shoes at its bottom to resist wear and tear.
The foot of the shoe represents zero reading.
Levelling staff may be
divided into two groups :-
1.Self
reading staff:
This staff reading is directly read by the instrument man through telescope.
1.Solid staff:
2.Folding staff :
A
staff of two pieces each of 2 m which can be folded one over the other.
3.Telescopic staff:
A staff of 3 pieces with upper one solid and lower two hollow.
The
upper part can slide into the central one and the central part can go into the
lower part.
Each length can be pulled up and held in
position by means of brass spring.
The
total length may be 4 m or 5 m.
2.Target staff:
If the sighting distance is more, instrument man finds it difficult to read self reading staff.
In
such case a target staff shown in may be used.
Target
staff is similar to self reading staff, but provided with a movable target.
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