NICET - Highway Construction Inspection Practice Exam

Which piece of equipment assists in establishing a survey instrument above an exact point?

1. Survey rod

2. Plumb bob

3. Laser level

4. Vernier

The correct answer is: Plumb bob

The piece of equipment that assists in establishing a survey instrument above an exact point is a plumb bob. A plumb bob is a simple yet effective tool made of a weight attached to a string. When it is suspended, the weight will hang directly downward, establishing a vertical line. This vertical reference is crucial in surveying because it allows the surveyor to align a survey instrument accurately over a specific point on the ground. In practical terms, when a survey instrument needs to be positioned over a precise point, the plumb bob is lowered until the point of the weight rests above the location being surveyed. This ensures that any readings or measurements taken from the instrument are directly applicable to the ground coordinates of the point directly below it. While other options like the survey rod, laser level, and vernier have their applications in surveying, they do not serve the specific purpose of maintaining vertical alignment above an exact point. The survey rod is mainly used for measuring horizontal distances, the laser level projects a horizontal or vertical plane but does not establish an exact point, and the vernier is used for precise measurement but is not directly related to positioning survey instruments above specific points.