Lecture 8 Chain Surveying

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What is the purpose of chain surveying?

To measure an area using satellite imagery

To measure an area using advanced GPS systems

To measure an area using linear measurements only (correct)

To measure an area using drone technology

Which of the following is NOT an equipment used in chain surveying?

Drone (correct)

Cross staff

Clinometer

Steel band

What are the two main types of chains used in taking measurements?

Günter’s chain and Plastic chain

Wire chain and Rope chain

Engineers chain and Bluetooth chain (correct)

Steel chains and Cable chains

What are tally markers used for in the chain?

To indicate every whole meter position Signup and view all the answers

Which type of chain is designed for hard usage and is sufficiently accurate for small surveys?

Engineers chain Signup and view all the answers

What is the width range of a Steel Band used in chain surveying?

$13 mm$ Signup and view all the answers

What is the purpose of a tape in surveying?

To measure distances accurately Signup and view all the answers

Which type of tape should never be used for work requiring great accuracy?

Linen Tapes Signup and view all the answers

What is the function of an arrow in surveying?

To mark temporary stations Signup and view all the answers

Why are pegs used in surveying?

To mark permanent points like intersection points of survey lines Signup and view all the answers

What is the main purpose of a ranging rod in surveying?

To mark points and enable visibility Signup and view all the answers

When is an optical square typically used in surveying?

For greater accuracy in setting out lines Signup and view all the answers

What is the purpose of a clinometer in surveying?

To measure angles of ground slopes Signup and view all the answers

What distinguishes an Abney level from a clinometer?

It measures slopes more precisely than a clinometer Signup and view all the answers

What is the purpose of establishing primary triangulation networks?

To measure angles with an accuracy of ±3 Signup and view all the answers

What were the primary trig points fixed at in the primary triangulation networks?

At the corners of triangles Signup and view all the answers

How was the secondary network of triangulation densified?

By establishing points at closer intervals connected into primary triangles Signup and view all the answers

What is the modern approach to measuring base lines in triangulation networks?

Using EDM equipment Signup and view all the answers

Why is scale error control important in triangulation networks?

To minimize errors in computing check base lines Signup and view all the answers

In what type of terrain is triangulation best suited?

Open, hilly country Signup and view all the answers

What should be done with steel bands/tapes when not in use?

Keep tapes reeled up Signup and view all the answers

Why is station marking important in a chain survey?

To facilitate easy relocation if the stations are moved Signup and view all the answers

What is the purpose of witnessing in a survey?

To facilitate easy re-location of a station at a later date Signup and view all the answers

Why are offsets taken perpendicular to chain lines in a survey?

To dodge obstacles on the chain line Signup and view all the answers

In selecting survey lines, why is a long base line recommended?

To form a base on which to build triangles Signup and view all the answers

What should be the angle range for triangles used in surveying?

Between 30o and 150o Signup and view all the answers

Why are check lines important in a survey?

To save time and avoid unnecessary duplication of lines Signup and view all the answers

What is the purpose of ranging in surveying?

To create a straight line for measurement Signup and view all the answers

How should gross errors in surveying be defined?

Errors caused due to carelessness or incompetence Signup and view all the answers

Why is it impossible to take observations completely free of small variations?

Despite best equipment and methods, errors always exist Signup and view all the answers

What is the primary method suggested in the text to eliminate systematic errors in measurements?

Calibrate the observing equipment Signup and view all the answers

Which type of errors cannot be removed from observation according to the text?

Random Errors Signup and view all the answers

What is the main cause of systematic errors according to the text?

Badly adjusted instruments Signup and view all the answers

What is one of the corrections suggested for linear measurements using a chain or tape?

Tension correction Signup and view all the answers

How can random errors in surveying be reduced according to the text?

By adopting statistical principles Signup and view all the answers

What is the effect of systematic errors on a series of repeated measurements under the same conditions?

+ve effect Signup and view all the answers