Mahatma Gandhi Institute of Tech. Education and Research Center TOPIC ADVANTAGES AND DISADVANTAGES OF PLANE TABLE SURVEYING AND ERRORS OF PLANE TABLE SYRVEYING Mahatma Gandhi Institute of Tech. Education and Research Center

Faculty Of Civil engineering department MGITER,NAVSARI. PRESENTED BY: GROUP ID :03 B.E. – 2nd, SEM- 3rd SR.NO. NAME ENROLLMENT NO. 1 BHATT HARDIK A. 130330106010 2 DESAI CHINTAN K. 130330106026 3 JOSHI JIGAR V. 130330106038 4 KHOLIYA YOGESH V. 130330106044 Faculty Of Civil engineering department MGITER,NAVSARI. GUIDED BY:- HITESH PATEL

Contents: Advantages of plane table surveying. Disadvantages of plane table surveying. Errors of plane table surveying.

ADVANTAGE OF PLANE TABLE SURVEYING

Advantages of plane table surveying. It is the most rapid method of surveying. 2. The plane table survey is quite suitable for plotting small scale maps directly filed. 3. The map can be prepared easily and dose not require any great skill. 4.As the plotting is done in the field, the field book is not required. So, the problem of mistakes in booking filed notes does not arise. 5.The surveyor can compare plotted work with the actual features of the area.

6.There is no possibility of overlooking any important object. 7.There is no possibility of overlooking any measurement as plotting is done in the field. 8.Errors in measurements and plotting can be easily detected in the field by taking suitable check lines. 9.Irregular objects may be represented accurately. 10.Inaccessible points can be easily located by intersection. 11.It is particularly useful in magnetic area where compass may not be used.

DIS ADVANTAGE OF PLANE TABLE SURVEYING

Disadvantages of plane table surveying. It is most inconvenient in rainy season and in wet climate. The instrument is very heavy and difficult to carry. The plane table is not suitable for accurate work as the fitting arrangement is not perfect. As no field data are taken, it becomes difficult to repot the plan to a different scale. The number of accessories required in such survey is large, and they are likely to be lost.

Errors of plane table surveying. Instrumental errors Personal errors Errors of plotting

The top surface of the plane table is not to the following causes. 1. Instrumental errors The top surface of the plane table is not to the following causes. The fiducial of the alidade might not be straight. The fitting of the table and the tripod are loose. The needle of the through compass may not be perfectly balanced. Also it may not be able to move freely due to sluggishness of the pivot point.

(v)The sight vanes are note perpendicular to the base of the alidade. (vi)The horsehair may be loose and inclined. (vii)The level tube is defective. (viii)The drawing paper is not of good quality.

2. Personal errors (i)The plane table is not properly levelled. (ii)The plane table is not accurately centred. (iii)The orientation of the table may not be proper. (iv)The table is not properly clamped. (v)The objects may not be bisected properly.

3. Errors of plotting (i) An incorrect scale may be used by mistake. (ii) A good quality pencil with a very fine pointed end may not have been used. (iii) Errors may occur due to incorrect measurements from not scale. (iv) Plotting errors may occur due to unnecessary hurry at the time of plotting and adopting wrong method of plotting.

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