In the method of repetition for measuring horizontal angles, to rotate the instrument without changing the readings,
Lower clamp screw is tightened and upper clamp is loosened
Lower clamp screw is loosened and upper clamp is tightened
Any one of the clamp screw is loosened
Both the clamp screws are loosened
Lower clamp screw is loosened and upper clamp is tightened
Functions of clamp screws :
• When the lower clamp screw is tightened, but the upper clamp screw is loosened, the instrument rotates on the inner axis with a relative motion between the two plates. The vernier reading changes.
• When the upper clamp screw is tightened but lower clamp screw is loosened, the instrument rotates on outer axis without any relative motion between the plates. The vernier reading do not change.
• If both the clamps are tightened, the instrument cannot rotate at all.
If we don't want to change the readings, the lower clamp screw is loosened and upper clamp is tightened.
Preparing students for success in a changing World.
We care about our students
RPSC-AE, RSMSSB-JE, SSC-JE, RRB-JE, PSU's