What is the function of optical plummet?

What is the function of optical plummet?

Concept: Optical plummet is used in a total station is used for accurate centering over a station. It has either a bullseye or cross hair sight for positioning the instrument over a survey marker or ground control point.

What are optical and laser plummet used for?

Optical and laser plummets are used for adjusting the instrument exactly on the station mark. The optical axis of the plummet is aligned with vertical axis of the instrument, when the instrument is removed through .

How do you plumb a tribrach?

Rotate the tribrach 120 degrees to line the optical plumb up with the next mark on the tripod head. Level the tribrach again and take another plumb sight, marking the plumb spot on the paper. Rotate the tribrach another 120 degrees and repeat the sighting process, again marking the plumb spot on the paper.

What is optical plummet?

A device on some transits and theodolites; used to center the instrument over a point, in place of a plumb bob, which moves in a strong wind.

What is laser plummet?

Laser plummets transfer points of reference during construction, particularly on large construction site with tall buildings, tunnelling and where accurate vertical alignment is critical. The visible beam provides visual reference points for aligning above and below the instrument.

What is a tribrach used for?

A tribrach is an attachment plate used to attach a surveying instrument, for example a theodolite, total station, GNSS antenna or target to a tripod.

How do you use a tribrach?

Using a tribrach

1. The tribrach is attached to the tripod and placed over the marker.
2. Looking through the optical plummet pick up two of the tripod legs and position the cross hairs over the marker.
3. Look through the optical plummet and using the thumbscrews put the cross hairs back over the marker.

How do optical plummets work?

The optical plummets are equipped with a telescope with peephole looking both up and down or only up. In these days there are many different works for many different instruments, but most surveying companies only want one universal instrument. Some total stations can be set to the vertical direction (zenith) with using a special angled eyepiece.

What is optical plumbing?

The optical plumbing is a basic geodetic method. Special instrument (optical plummet) is used. The optical plummets are equipped with a telescope with peephole looking both up and down or only up. In these days there are many different works for many different instruments, but most surveying companies only want one universal instrument.

Can a plumb bob be used to center the tripod?

TIP Although the optical plummet will be used to center the instrument, a plumb bob can be used to center the tripod. An optical plummet is a telescopic device for allowing the surveyor to center the antenna over a point.

How do you adjust the optical plumb on a tribrach?

If the optical plumb is out of adjustment, the three marks will form an equilateral triangle. Put a mark at the center of that triangle. Adjust the plumb. Most tribrachs have two small adjusting screws on the optical plumb arm under the instrument.