State any four sources of errors in compass survey

State any four sources of errors in compass survey 
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2 Answers

Answer :

Following are the sources of errors in compass survey1. Instrumental surveya. Needle may not be perfectly straight and might not be balanced

properly over the station.

b. Graduations of the rings may not be uniform.

c. The ring may not rotate freely, due to head of the pivot being broken or may be eccentric.

d. The sight vane may not be vertical

e. Horse hair may not be straight or vertical.

2. Personal errorsa. centering may not be done perfectly over the station.

b. Graduated ring may not be leveled.

c. The object might not be bisected properly.

d. Observer may be carrying magnetic substances.

3. Other sources of substancesa. There may be attraction due to the presence of magnetic substances near the station.
b. Magnetic field may vary on account of some natural causes. 
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Answer :

Following are the sources of errors in compass survey1. Instrumental survey-

 a. Needle may not be perfectly straight and might not be balanced properly over the station.

 b. Graduations of the rings may not be uniform.

 c. The ring may not rotate freely, due to head of the pivot being broken or may be eccentric.

 d. The sight vane may not be vertical

 e. Horse hair may not be straight or vertical.

2. Personal errors-

 a. centering may not be done perfectly over the station.

 b. Graduated ring may not be leveled.

 c. The object might not be bisected properly.

 d. Observer may be carrying magnetic substances.

3. Other sources of substances-

 a. There may be attraction due to the presence of magnetic substances near the station.

 b. Magnetic field may vary on account of some natural causes. 
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