- A spirit level, bubble level, or simply a level, is an instrument designed to indicate whether a surface is horizontal (level) or vertical (plumb).了解详细信息:A spirit level, bubble level, or simply a level, is an instrument designed to indicate whether a surface is horizontal (level) or vertical (plumb).en.wikipedia.org/wiki/Spirit_level
If line of sight of the telescope can be reversed through the rotation of telescope by 180° about the trunnion axis in vertical plane, the theodolite is known as transit theodolite. This type of theodolite is commonly used for surveying .
constructionhow.com/theodolite-surveying/A theodolite works by combining optical plummets (or plumb bobs), a spirit (bubble level), and graduated circles to find vertical and horizontal angles in surveying. An optical plummet ensures the theodolite is placed as close to exactly vertical above the survey point. The internal spirit level makes sure the device is level to to the horizon. The
gcekbpatna.ac.in/assets/documents/lecturenotes/S…This is achieved by adjustment of three foot screws and observing a precise tube bubble. This bubble is known as the plate bubble and is placed on the upper plate.
www.skdavpolytech.ac.in/news_files/surveying___…A spirit level, bubble level, or simply a level, is an instrument designed to indicate whether a surface is horizontal (level) or vertical . Two basic designs exist: tubular (or linear ) and bull's eye (or circular ).
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Spirit level - Wikipedia
Open Access Surveying Library - Chapter E. Bubbles, …
Most surveying equipment has a bubble to facilitate being correctly oriented to gravity. Two kinds of bubbles are used: bubble tube and circular bubble. Figure E-1 shows top and side view of both.
Surveying and Leveling: LESSON 15. Theodolite …
The plate bubble is brought to the centre with the help of food screws (in the usual manner). Then the altitude bubble is brought to the centre by means of a clip screw. At this position the line of collimation is exactly horizontal. To …
Spirit level | tool | Britannica
Transit Theodolite | Instruments | Surveying - Engineering Notes …