This website uses cookies to improve your experience while you navigate through the website.

To measure the horizontal angle AOB by repetition: (i) Set up the theodolite at station -point O and level it accurately. Divide the sum by the number of repetitions and the result thus obtained gives the correct value of the angle AOB. Content Guidelines 2. (v) Loosen the upper clamp and turn the telescope clockwise until the line of sight is set nearly on the right hand object (B). Errors Eliminated by Measuring the Horizontal Angles by Repetition: (i) Errors eliminated by changing face of theodolite: (a) Error due to the line of collimation not being perpendicular to the horizontal axis of the telescope. [gravityform id="1" title="false" description="false" ajax="true"]. are introduced. (ii) Set the vernier A to the zero or 360° of the horizontal circle so do this, loosen the upper clamp and tum the upper plate until the zero of vernier A nearly coincides with the zero of the horizontal circle. The reading of the vernier A which was initially set at zero gives the value of the angle AOB directly and that of the other venier B by deducting 180°. (iv) Loosen the upper clamp and turn the telescope clockwise until the point B is exactly sighted by using the upper tangent screw. Read both verniers. Image Guidelines 4. In this method; the same angle is added several times mechanically and the correct value of the angle is obtained by dividing the accumulated reading by the number of repetitions. Account Disable 12. Check the vernier readings which must be the same as before. It may be set at any other reading, and the difference between the initial and the final readings of the vernier A will give the value of the angle AOB. This is done to avoid errors of graduation. Read both verniers. Visit our updated, 2020 Point of Beginning Aerial & UAV Research. By visiting Bring the point A into exact coincidence with the point of intersection of the cross-hairs at diagram by using the vertical circle clamp and tangent screws. The mean of the two vernier readings (after deducting 180° from the reading on vernier B gives the value of the required angle AOB.). Read the vernier B and record both vernier readings. 3.


(ix) Change the face of the instrument (now the face will be right). (iii) Direct the telescope to some well-defined object (P) or say, the station point A, which is known as the ‘Reference object’.

In this operation, the lower clamp and its tangent screws should not be touched. Bisect it accurately by using the lower clamp and its tangent screw. this website. (i) Set up the theodolite at station-point O and level it accurately.

Visit our updated, This website requires certain cookies to work and uses other cookies to help you have the best experience.

Content Filtration 6. Reiteration is another precise and comparatively less tedious method of measuring the horizontal angles. The vernier A is initially set to zero for convenience only.

(x) Set the vernier A to a reading other than 0°, say, 60° or 90°).

Design, CMS, Hosting & Web Development :: ePublishing, This website requires certain cookies to work and uses other cookies to help you have the best experience. Repeat exactly in the same manner and find another value of the angle AOB. The final reading of the vernier A should be the same as its initial reading. (v) Read both verniers- The object of reading the verniers is to obtain the approximate value of the angle. There is therefore, no advantage in increasing the number of observations beyond a certain limit. (v) The error due to dishevelment of the bubble can be minimised by taking precautions in levelling. If you do not agree to the use of cookies, you should not navigate this website, certain cookies have already been set, which you may delete and (ii) Set the vernier A to zero or 360° by using the upper clamp and its tangent screw.

(vi) Finally, close the horizon by sighting towards the reference object (P) or the station-point A.

By closing this message or continuing to use our site, you agree to the use of cookies. I wouldn't do it for traversing, though. (ii) Set the vernier A to 0 or 360° by using the upper clamp and its tangent screw. (iii) Check the reading of the vernier A and see whether it still reads zero, and then read the other vernier B. But opting out of some of these cookies may affect your browsing experience. (vi) Loosen the lower clamp and turn the telescope clock-wise until the object (A) is sighted again. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. Turn the instrument and direct the telescope approximately to the left hand object (A) by sighting over the top of the telescope. Visit our privacy Closing the Horizon - A technique in traversing control for horizontal measurements. Bisect A accurately using the lower tangent screw. The final readings after n repetition should be approximately n x (50°4′). However, it cannot be said that any desired degree of accuracy can be obtained by increasing the number of repetitions considerably because the errors due to frequent clamping etc. (vii) The vernier A should now read 360°. (Suppose the mean reading is 50°4′). (viii) Repeat the process until the angle is repeated the required number of times (usually 3).

Check the reading at vernier A which should still be 0 or 360° and note the reading at vernier B. Repetition Method. This site uses cookies. (iii) Error eliminated by measuring the angle on different parts of the circle: (iv) The errors in the pointing tend to compensate each other and the remaining error is minimised by the division. By closing this message or continuing to use our site, you agree to the use of cookies. The observations are recorded in the tabular form as given in Table 9.1. (The face of the instrument should be left.). Prohibited Content 3.
9.6.) You also have the option to opt-out of these cookies. Tighten the lower clamp and bisect A exactly by turning the lower tangent screw. (b) Error due to the horizontal axis of the telescope not being perpendicular to the vertical axis. These cookies will be stored in your browser only with your consent. (vii) Loosen the upper clamp, turn the telescope clock-wise and again sight towards B. Bisect B accurately by using the upper tangent screw. Reiteration Method.

It is generally preferred when several angles are to be measured at a particular station. There are three methods of measuring horizontal angles: 1. Horizontal Angles, Measurement of Horizontal Angles, Surveying, Theodolite Surveying. Copyright 10.

(xiii) The mean of the two results for each angle is taken as its true value. The mean of the two vernier readings (after deducting 180° from the reading at vernier B) will give the value of the angle AOB. The method provides an easy way for a beginner to test instrument readings and pointings. Ordinary Method. Suppose it is required to measure the angles AOB, BOC and COD. (iv) Having sighted the object A, see whether the vernier A still reads zero.

(c) Error due to the line of collimation not coinciding with the axis of the telescope.

and cookie policy to learn more about the cookies we use and how we use your block. In this way, angles can be measured to a finer degree of accuracy than that obtainable with the least count of the vernier.

Three repetitions with face left and three repetitions with face right are quite sufficient except in cases of very precise work. This method consists in measuring the several angles successively, and finally closing the horizon at the starting point. This method is used for very accurate work. The mean of the two vernier readings gives the second value of the angle ABC which should be approximately or exactly equal to the previous value. If large, the readings should be discarded and a new set of readings be taken. (viii) The mean of the two values of the angle AOB, one with the face left and the other with the face right, gives the required angle free from all instrumental errors. This is done to detect the error caused by turning the wrong tangent screw. Alternatively bring the vertical cross-hair exactly on the lowest visible portion of the arrow or the ranging rod representing the point A in order to minimise the error due to non- verticality of the object. Then tighten the upper clamp and by turning its tangent screw, bisect B exactly. (iv) Loosen the upper clamp, turn the telescope clock-wise and bisect the right hand object (B) exactly by using the upper clamp and its tangent screw. Before uploading and sharing your knowledge on this site, please read the following pages: 1. Lovingly crafted and maintained by. Then to measure these angles by reiteration method: (i) Set up the instrument over station point O and level it accurately. : To measure horizontal angle AOB: (i) Set up the theodolite at station … Plagiarism Prevention 5. Uploader Agreement.

(v) Similarly bisect C and D successively, read both verniers at each bisection, find the values of the angles BOC and COD. Closing the horizon is good for spur points, to show that a mistake wasn't made. Then loosen the lower clamp, direct the telescope to the left hand object A, and bisect A exactly by using the lower clamp and its tangent screw. Privacy Policy 9. (xii) Close the horizon and apply the necessary correction to all the angles as before. Such procedure (closing the horizon) can be applied even when only one angle is measured.

(xi) Again measure the angles in the same manner by turning the telescope this time in the counter-clockwise direction to compensate or slip and errors due to twisting of the instrument.


Theme Of Beowulf, Ashley Butler Instagram, How To Get A Baby Pig To Poop, Jackie Appiah Son, Diamondback Edgewood For Sale, Gas Cap Hisses When Removed, Adele Height Cm, How Tall Is Historia Reiss In Feet, Carder Chair Parts, Don't Call Me White Girl Ig, Italian Lawyer Jokes, 5 Building Blocks Of Investigation, Sum Of Angles Of A 6 Pointed Star, Kate Mcshane Ian, Brit Selwood Age, Looking At My Rollie It's About That Time Big Tymers, Toilet Paper Shortage 1943, What Happened To Spoony, Wallander Before The Frost Plot, Weyes Blood Wild Time Lyrics Meaning, Captain Derrick White, Affirm Pitch Deck, Lost The New Man In Charge 720p, Kristen Welker Wedding, Empty Bottles Walmart, Antonia Reininghaus Who Fatally Poisoned Their Common Seven Year Old Daughter Johanna In 1987, Mt Colden From Upper Works, Minecraft School Map With Dorms, East Side Cocktail, Best 90s Bass Songs, Dalmatian Mastiff Mix, Steven Meteor Falls Emerald, Social Security Disability Status Check Online, Lumos Font For Google Docs, Do Possums Attack Chickens Australia, Wandering Tattler Call, Arctic Food Web Consumers, Rza Net Worth 2020, Pastor E A Adeboye Phone Number, Cyberpsychology Dissertation Ideas, Mcgraw Hill Connect Promo Code Reddit 2020, Aesthetic Bios For Amino, Dhanyu Devado Lyrics, Emma Forbes Net Worth, Why Do You Want To Join The Honors Program Essay, Mathieu Lafontaine Wikipedia, 1p_jar Cookie Description, Cordeliers District Paris Map, Farmville 2 Cheats 2020, Family Crisis Examples, Radium Girls 2020, Watchespn Apk Crack, Dave Van Horn Salary, Ithaca Journal Classifieds, Let It Go Wildest Dreams, Caroline Matthews Ceo, Dear Mama Wanda Coleman, Best Direction For House To Face In Florida, Dr Maya Rockeymoore Cummings Net Worth, Quantitative Research Title Examples For Stem Students, Caleb Kids Show, Don Julio Price, Borderlands 2 Shift Codes Nintendo Switch, Leslie Torres Wikipedia, Delaware Memorial Bridge Jumper, Like Everybody Else Chords,