What is check line and tie line?
Answer: Check line joins the apex of main triangle with any fixed point on other two sides of triangles. Tie line joins two fixed points on main survey lines and it checks the accuracy of surveyinf as well as it helps in showing the details of the surveyed field.
What is base line in chain survey?
Base Line: The longest chain line in chain surveying is often called the base line. It is the most Important line, fixes up the directions of all other lines. Base Line should pass through the center of the area. It is measured very accurately, and all the necessary corrections are applied.
What is the necessary of running check line in the chain surveying?
Check (Proof) Lines It joins triangle apex to some fixed points on any two sides of a triangle. It is used to examine the accuracy of the framework. The length of check line measured on ground shall be consistent with its length on the plan.
How many types of lines are there in chain survey?
Baseline, Tie line, Check line, Main survey stations, Tie Stations, Location sketches of survey station. Two men are required to measure the distance between two places A and B by a chain.
What is the principle of survey?
Surveying is the process of finding the relative position of various points on the surface of the earth by measuring distance among them and setting up a map to any reasonable scale.
What are the two basic principles of surveying?
Two basic principles of surveying are: • Always work from whole to the part, and • To locate a new station by at least two measurements ( Linear or angular) from fixed reference points.
What is the basic principle of chain surveying?
Chain surveying is the type of surveying in which only linear measurements are made in the field. The main principle of chain surveying or chain triangulation is to provide a framework consist of number of well-conditioned triangles or nearly equilateral triangles. It is used to find the area of the field.
What is the principle of plane tabling?
Plane table surveying is based on the principle that lines drawn during plotting always lie parallel to the corresponding lines actually present on the ground i.e the principle of plane table surveying is parallelism.
What instrument is used for centering the table?
3) A compass is for marking the north direction on the paper . 4) A plumbing fork with a plumb bob for centering the table.
What is 3 point problem in surveying?
In surveying, a method used to orient underground workings via three plumblines suspended in a vertical shaft. ii. The problem in plane table surveying of locating precisely the point at which the table is set up, using three fixed points that are visible from the plane table.
How many types of a compass are used in surveying?
two
What are 3 types of compass?
Compasses normally come in three different styles.
- Baseplate Compass. The most typical compass is normally referred to as a Baseplate Compass.
- Mirrored Baseplate Compass.
- Lensatic Compasses.
What is the principle of compass?
The magnetic compass is working with the principle of Earth’s Magnetic Field and shows the magnetic north and south. The simplest form of compass consists of a magnetized needle free to rotate in a horizontal plane. Such a needle tends to settle in the magnetic meridian.
What are the two types of compass?
Types of compass
- Base plate compass. It is the most affordable compass.
- Thumb compass. Thumb compass on left, base plate on the right.
- Card compass. Card compass or marine compass is commonly used in ships and boats.
- Prismatic compass.
- Gyro compass.
- Astrocompass.
- Solid state compass.
- GPS compass.
What are the types of surveying?
Based on various types of instruments used, surveying can be classified into six types.
- Chain surveying.
- Compass surveying.
- Plane table surveying.
- Theodolite surveying.
- Tacheometric surveying.
- Photographic surveying.
Which instrument is used for ranging in surveying?
A ranging rod (or range rod) is a surveying instrument used for marking the position of stations, and for sightings of those stations, as well as for ranging straight lines.
Whats is a compass?
A compass is a device that indicates direction. It is one of the most important instruments for navigation. Magnetic compasses consist of a magnetized needle that is allowed to rotate so it lines up with the Earth’s magnetic field. The ends point to what are known as magnetic north and magnetic south.
What are the advantages of compass surveying?
Advantages
- They are portable and light weight.
- They have fewer settings to fix it on a station.
- The error in direction produced in a single survey line does not affect other lines.
- It is suitable to retrace old surveys.
Which liquid is used in prismatic compass?
5.6 Liquid – Good quality kerosine, isopropyl alcohol or anhydrous ethyl alcohol shall be used as the liquid.
What is the full name of prismatic compass?
Surv.
Which liquid is used in compass?
Modern compasses usually use a magnetized needle or dial inside a capsule completely filled with a liquid (lamp oil, mineral oil, white spirits, purified kerosene, or ethyl alcohol are common).
Which bearing is used in prismatic compass?
For each survey line in the traverse, surveyors take two bearings that is fore bearing and back bearing which should exactly differ by 180° if local attraction is negligible. The name Prismatic compass is given to it because it essentially consists of a prism which is used for taking observations more accurately.