Instrument for Accurate Centering in Plane Table Survey

The instrument used for accurate centering in plane table survey is a plumbing fork.

Plumbing Fork

A plumbing fork is a small metallic fork with two prongs that are used to suspend a plumb bob. The fork is attached to the upper side of the table with the help of a screw. The plumb bob is suspended from the fork and is used to find the exact center of the table.

Steps to Use Plumbing Fork

The following steps are involved in using a plumbing fork for accurate centering in plane table survey:

1. Place the table on the tripod stand.

2. Fix the plumbing fork on the table with the help of a screw.

3. Suspend the plumb bob from the fork.

4. Adjust the position of the table until the plumb bob is exactly at the center of the table.

5. Verify the position of the plumb bob using a through compass.

6. Once the exact center of the table is found, the surveying work can begin.

Advantages of Using a Plumbing Fork

Using a plumbing fork for accurate centering in plane table survey has the following advantages:

1. It is a simple and easy-to-use instrument.

2. It provides accurate and reliable results.

3. It is a cost-effective solution for accurate centering in plane table survey.

Conclusion

A plumbing fork is a small but important instrument for accurate centering in plane table survey. It is easy to use and provides accurate results, making it a valuable tool for surveyors.