Plane Table Surveying with Methods
Plane Table measure is employed in ad-hoc measure and coming up with things. In this, survey fortification and plotting work are completed at the same time. Therefore, there's no would like for work. this is often best tailored to things wherever high exactitude isn't needed. Thereby, it's greatly helpful for small-scale mapping operations.
Instruments utilized in surveying instrument measure
The surveying instrument survey technique uses terribly straightforward instruments. These square measures are accessible all over.
Drawing Board
It's a board fabricated from seasoned wood. they're accessible in several sizes. Generally, the sphere work is completed in forty cm by thirty cm boards. They conjointly use the seventy-five cm by sixty cm boards, for larger work. within the field, a stand is placed beneath the board with a ball socket in it. this permits the surveyor to draw on the board from any angle.
Alidade
associate degree alidade is essentially a ruler with a telescope. this is often used on the drafting board to draw lines and rays consistent with the sphere. The alidade might also have a level thereon.
Compass
A troublesome compass is employed to seek out the longitude of the place. Generally, the compass utilized in survey work conjointly has 2 bubble tubes at right angles to every different.
Plumbing Fork
It's a rod with a plumb ob connected to at least one finish. this is often accustomed to making sure that different instrumentality is aligned utterly vertically, once required.
Spirit Level
It's a tube of liquid with a bubble within it. The tube is slightly bulging within the middle. This lets the bubble keep within the middle of the tube once the extent is utterly horizontal. this is often accustomed to certifying the drafting board, or different instrumentality square measure placed horizontally.
Waterproof cowl
A water-resistant cover is employed to hide the paper on the drafting board from rain or different splashes and dirt. this is often usually fabricated from soft synthetic resin.
Drawing sheet
Glorious quality paper ought to be used because of the drawing sheet. this is often a result of the sheet should face heaps of rough use within the field. Also, it should get collapsed and roll persistently. The paper usually used on drawing boards encompasses a tendency to stretch and contract because of fixing humidness. For this reason, the paper ought to be seasoned every week before usage.
Tripod
The stand is crucial in measure as a result of it helps mount all different instruments, particularly the drafting board.
The tripod may be fitted with different sorts of mounts as needed.
- Advantages of Plane Table Surveying
- Both field and plotting work done at once
- Maintaining field notes not required
- Separate office work for plotting not required
- Direct measurements not required since they are taken graphically
- Suitable for magnetic areas where compasses are not reliable
- Takes less time and less investment
- Preparing small-scale maps are easiest with this
- Contours and irregular objects are more easily represented
- A tangent clinometer can also help find out reduced level of points
- Not much skill required to complete the survey
Disadvantages
This method is not good for accurate surveying. Also, you cannot do this in wet climates. Large areas cannot be covered by this survey as well. Not to mention handling a drawing board in the field may be very inconvenient.