Compass Survey

Table of Contents

What is Compass Surveying?

Additionally, survey that is mainly done with the help of a compass is called a compass survey.

Process of Compass Surveying

However, Compass Surveying device has a needle or rod. Similarly, This rod has a magnet on its head. Specifically, The rod can rotate Easily on the pivot of the compass. Moreover, No matter where it is Spinning. Likewise, it always looks for the direction of the wind. Similarly, It is also referred to as direction.
Additionally, Surveyors conduct compass surveys using Navigating. Likewise, Traverse forming means Linking the points in the plot by means of a series of straight lines.
Major parts of a Prismatic Compass are:

  • Magnetic needle.
  • Graduated ring.
  • Adjustable mirror.
  • Sliding Organization for the mirror.
  • Object vane.
  • Eye vane.
  • Metal box.
  • Glass cover.
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Compass Surveying

Similarly, Compass Measuring is surveying in which surveyors determine the position of an object’s location. Likewise, They determine the angular Quantities by a compass and linear Quantities using a chain or tape. Specifically, Compass survey is effective in the following circumstances:
Firstly, For a large Assessing area, where chain Measuring is not possible for Measuring, therefore, compass Assessing is an effective solution.
Moreover, The plot for Gauging has numerous obstacles and undulations which prevent chaining.
But also, Indeed, when there is a time limit for the survey, compass survey is the typical choice.

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Likewise, Places containing an iron core, power lines, etc. Similarly, Compass survey is not possible there. Therefore, Cause compass usually attracts magnets due to their natural properties and electromagnetic properties respectively. Likewise, The traversing method is the process of Compass surveying. Additionally, a traverse is created by connecting points on the plot through a series of straight lines.

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Define compass surveying

However, To find out the magnetic bearing of survey lines-We use the magnetic compass. Likewise There are two bearing system, One of them is the Whole Circle Bearing (W.C.B) system and another one is the Quadrantal Bearing (Q.B) system. Furthermore, It’s basically depends on the type of compass we are using. Similarly The basic principle of a magnetic compass surveying is a strip of steel or iron which is magnetized and pivoted exactly at the center. As a result, it can swing freely and then it can establish itself in the magnetic meridian at the place of arrangement.

Compass Survey

Major types of the magnetic compass are:

1. Prismatic compass
2. Surveyor’s compass
3. Level compass

Prismatic compass survey Instrument:

Major parts of a Prismatic Compass are:

  • Magnetic needle
  • Graduated ring
  • Adjustable mirror
  • Sliding arrangement for mirror
  • Object vane
  • Eye vane
  • Metal box
  • Glass cover
  • Horsehair
image 1 6

Define compass surveying

However, To find out the magnetic bearing of survey lines-We use the magnetic compass. Likewise There are two bearing system, One of them is the Whole Circle Bearing (W.C.B) system and another one is the Quadrantal Bearing (Q.B) system. Furthermore, It’s basically depends on the type of compass we are using. Similarly The basic principle of a magnetic compass surveying is a strip of steel or iron which is magnetized and pivoted exactly at the center. As a result, it can swing freely and then it can establish itself in the magnetic meridian at the place of arrangement.

Compass Survey

Major types of the magnetic compass are:

1. Prismatic compass
2. Surveyor’s compass
3. Level compass

Prismatic compass survey Instrument:

Major parts of a Prismatic Compass are:

  • Magnetic needle
  • Graduated ring
  • Adjustable mirror
  • Sliding arrangement for mirror
  • Object vane
  • Eye vane
  • Metal box
  • Glass cover
  • Horsehair

There are two types of adjustments available for prismatic compass:

1. Temporary adjustment
2. Permanent adjustment

Temporary adjustments of Prismatic compass surveying instrument

  • Centering: Moreover It is the process of fixing the compass exactly over the station. Centering is usually done by adjusting the tripod legs. In fact Also, a plumb-bob is used to judge the accurate centering of instruments over the station.
  • Leveling: The instrument has to be leveled for use in hand or mounted over a tripod. Similarly For use in the hand, the graduated disc should swing freely and appears to be completely level in reference to the top edge of the case. on the other hand, using the tripod, they usually have a ball and socket arrangement for leveling purposes.
  • Focusing the prism: Specifically Prism can be slide up or down for focusing to make the readings clear and readable.

Permanent adjustments of Prismatic compass surveying instrument

Same as the surveyor compass.

Prismatic Compass Surveying and Direction Determination

A prismatic compass is a special type of compass used for determining directions and measuring angles. The process of direction determination through prismatic compass surveying is accomplished through the following steps:

1. Preliminary Preparation

  • Gathering Equipment: Prepare a prismatic compass, tape (or chain), field book, and other necessary tools.
  • Site Selection: Go to the designated site where there are no obstacles for the compass to work.

2. Calibration of the Compass

  • Calibration: Verify whether the compass needle is functioning correctly. Due to magnetic declination, the needle may not provide accurate directional guidance. Calibrate the compass if necessary.

3. Direction Determination Process

  • Selecting a Reference Point: First, select a reference point, such as a tree, building, or permanent marker.
  • Using the Compass:
  • Hold the compass in a level position and ensure it is properly leveled.
  • Look towards the reference point and rotate the compass needle. The direction indicated by the needle is your bearing.
  • Recording the Bearing:
  • Note the bearing (in degrees) from the position of the needle on the compass scale.
  • Example: 0° for North, 90° for East, 180° for South, and 270° for West.

4. Distance Measurement

  • Measuring Distance: After determining the direction using the compass, measure the distance between the points using tape or chain. Record this information in the field book as well.

5. Map Preparation

  • Recording Information: Note all directional and distance information in a field book or notebook.
  • Creating a Map: Based on the recorded information, create a map or plan that will determine the positions of the points based on direction and distance.

6. Review and Analysis

  • Review the results of the survey and make corrections if necessary.

Conclusion

Direction determination using a prismatic compass is an effective method that helps establish relationships between different points of land. It is essential for land surveying, land management, and other construction activities.