# errors in compass surveying

The Least Count of this compass is 30 minutes that means the instrument can show readings only in multiples of 30 minutes and Least Count is a minimum value that any instrument can read. 5.28 b) equal in length to the perimeter of the traverse to any convenient scale and set off along it the distances AB’, B’C’, C’D’, D’E’ and E’A’ equal to the lengths of the sides of the traverse. Declination can be positive or negative. Systematic errors are caused by the surveying equipment, observation methods, and certain environmental factors. JNTU College of Engineering, Hyderabad • ELECTRICAL 101, Massachusetts Institute of Technology • BOSTON 6.002x, Columban College - Olongapo City • BSEE 101, question papers of four year b. tech iv semester regular examinations june - 2013. different elements of a simple circular curve. Personal errors.

To run a traverse line the compass is generally used and with respect to magnetic north compass calculates bearings of lines.

How much will a midwifery schooling cost? If it is not properly observed while taking measurements, the results will be incorrect. This preview shows page 3 - 6 out of 68 pages.

There are two types of this compass such as; Fixing the compass exactly over the station centering is the process of fixing and by adjusting the tripod legs centering is done usually.

The error produced in a single survey does not affect other lines. 4. The areas enclosed by various contours on the upstream side of a dam are given.

Local attraction can be minimized using following methods: This method is based on the difference of fore and back bearings.

To various errors like errors adjoining to magnetic meridian, local attraction etc, it is easily subjected.

Ignore the, (a) State what errors are eliminated by repetition method. May 2005 SURVEYING EQUIPMENT, MEASUREMENTS AND ERRORS 3.1(1) Chapter 3 Surveying Equipment, Measurements and Errors 3.1 EQUIPMENT The procurement and maintenance of surveying equipment, tools and supplies are important parts of the Department’s survey effort.

If the magnetic meridian is happened to be on the right side or eastern side of true meridian, it is termed as positive or eastern. The following are the kinds of error which may occur while taking readings with a  compass; INSTRUMENTAL ERRORS; the needle may not be perfectly straight and might not be balanced properly. The R.Ls of, the tops of pegs A and B are 89.620 and 89.222m respectively.

The horizontal projections of these lines can be termed as magnetic meridian. Proper care …

In this method, the correction is applied to the lengths as well us to the bearings of the lines in proportion to their lengths Therefore, this method is also known as proportionate method.

Find, (b) the readings that would have been obtained had there been no collimation, 4. (a) What is meant by degree of curve. These result from imperfection in the construction or adjustment of surveying instruments, and movement of their individual parts. 5.28 (c)]. A level set up on extended line BA in a position 70m from A and 100m from B, reads 1.684 m on a staff held at A and 2.122 on a staff held at B, the bubble having, been carefully brought to the center of its run before each reading.

Errors may also be due to variations in natural phenomena such as temperature, humidity, wind, refraction and magnetic declination.

The lines of force in this magnetic field are run from south to north. PRECATIONS TO BE TAKEN IN COMPASS SURVEYING; the following precautions should be taken while  conducting a compass  traverse; the centering should be done perfectly. How do you put grass into a personification? Some more details of civil surveyor course in rawalpindi are as under. There are following errors in the compass surveying such as; There are some instrumental errors such as; There are also some natural errors such as; There are following advantages of the compass surveying such as; There are also some disadvantages of compass surveying such as; Your email address will not be published. To do this, draw lines parallel to the closing error at each of the stations B’, C, D’, E’ and set off along them the respective intercepts on the proper side.

As nearly level as can be judged the instrument should be held near and if the needle does not oscillate it means that it is touching the glass lid and not been vertically held.

When large areas involved, methods of chain surveying is not sufficient. The errors are caused in sighting and reading if the plane of sight not being vertical. To adjust it, draw a line AA’ (Fig. Eliminate or correct all systematic errors by frequent calibration and adjustment of the instruments Minimize the random errors by using good instrumentsandfieldprocedures. But when the error is found to be within the permissible value, the traverse may be adjusted graphically by one of the following two methods: This method is the graphical application of Bowditch’s rule. Then the needle comes to rest and to cut the image of the graduated ring is noted by the reading at which the hairline produced appears. Disclaimer 8.

Then the intercepts B’b, C’c, D’d and E’e represent the corrections at B’, C, D’ and E’ in magnitude only but not in direction. The errors are also caused by imperfect sighting of ranging rods and inaccurate leveling. Report a Violation 11.

In this case, it will be noticed, that the stations will have to be shifted downwards.

Error Occurs in Compass Surveying of Land | Compass Surveying| Surveying. Plagiarism Prevention 5. The area where dip is 90˚ because the north latitude is 70˚ and west longitude is nearly 96˚ is called North magnetic pole. When only the magnitude of correction to be applied at each station is required, draw A’a perpendicular to A A’ and equal in length to the closing error [fig. the graduated ring may not be leveled. Image Guidelines 4. For example, AB’C’D’E’A’ [fig. The readings may be taken or entered carelessly .the observer may be caring magnetic substances. Reading may not be accurate if the magnetic needle is not perfectly straight. Dead Reckoning and Compass SensorsDead reckoning is the mathematical process of calculating the current position of an object based on knowledge of the location of its previous position and, What are the sources of errors in compass survey. Personal Errors

Code No R21015R10 Set No 2 II BTech I Semester Regular Examinations November, (a) a) Explain clearly the points of difference between the prismatic compass and, (b) What are the sources of errors in compass Surveying and what precautions, (b) The following bearings were taken in traversing with a compass. What is the best way to fold a fitted sheet?

Required fields are marked *. if the instrument is used as in hand or mounted over a tripod the instrument has to be leveled. Then two bearings of least discrepancy is selected in such a way that the difference of them is closest to 180˚. the horse hair may not be straight and vertical.

Compass Surveying Unit-II 2. Save my name, email, and website in this browser for the next time I comment.

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