Sprit level or bubble levels surveying is the direct surveying by using bubble or spirit level. It is used to make sure the leveling instrument is horizontal and then measure the backsight reading And foresight reading then get the reduced level from the different of those reading.it9 is commonly used for road survey and canal survey
What is spirit leveling in survey work? What is spirit leveling in survey work?
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Spirit leveling is a process of using a spirit level to measure the horizontal plane to determine height differences above or below that plane.
It is the first and foremost step usually done in any kind of land surveying work.
Leveling is also used to measure the height differences between the high and low points of land with reference to the horizontal plane defined by the spirit level.
Spirit level is an instrument used in surveying.
If you are talking about spirit level, then it is an instrument used to level the apparatus of surveying vertically. There is liquid in it with a bubble. It is present on every apparatus of surveying.
But if you are talking about spirit leveling, then it was a method for calculating elevation.
Spirit Levelling is an old method and exact method to obtain data for small land area, and generally, it is used for roads, railway tracks, and canal work.
In this method, the spirit level is used to determine the horizontal plane to measure a height difference above and below that horizontal plane. You can understand better from the below figure.
Spirit leveling (sometimes simply referred to as leveling) is a process to find out the elevation of the desired point with the help of the known elevation of a point with the use of a level instrument and a vertical staff with markings.
The instrument is kept somewhere between the two points and is exactly horizontally leveled with the help of a bubble level on top of the instrument. Now the staff readings with the staff at both the points are seen thought the scope in the level instrument. The difference in these readings is the difference in the elevations. Necessary addition or subtraction is done to calculate the desired elevation.
It is an old conventional yet very accurate technique. It generally gives an accuracy down to 1mm in RL.
Spirit level is used to check whether an instrument is in Horizontal position or not.
If the bubble in the above figure is in the center, that indicates the surface over which the spirit level is placed is Horizontal.
In advanced instruments like dumpy level, auto level, theodolite, and total station, this comes along with the instrument itself and is called a bubble tube.
Whereas for older equipment like plane table surveying, this spirit level is used separately.
Spirit leveling is literally the act of using a level of the spirit to evaluate a horizontal plane to calculate variations in height above or below that plane. … The leveling is achieved by calculating the differences in height between different terrain locations with respect to the horizontal plane specified by the spirit level.
It is that part of leveling where the vertical dist’s as for a horizontal line (⊥ to direction of gravity) might be utilized to decide the relative contrast in height between two adjacent points. A horizontal plane of sight tangent to level surface at any pt is promptly settled with the help of spirit level or a level vial. In spirit leveling, a spirit level and a telescope are taken and vertical dist’s are estimated by seeing on graduated poles set on the pts. The technique is otherwise called direct leveling. It is the most exact strategy for deciding rises and the one most regularly utilized by engineers.
In surveying, spirit level is used to check the alignment of your table you are working on casting your observations on. The instrument is basically a tube filled with liquid. It has a flat base, so that one can rest it on the table.
It is used as, you put the instrument on the table and check where the bubble is in the center, if not, then you have to move the legs of the table till you get the bubble in the center. Once it is in the center, your table is parallel to the ground, along horizontal axis.
- Sprit levelling is the measurement of elevation difference between two adjacent points by measuring the vertical distances wrt perpendicular to gravity.
- A horizontal plane sight tangent to the level surface is easily established utilizing a spirit level. In spirit leveling, a spirit level and a sighting device are combined, and vertical distances are measured by observing graduated rods placed on the points.
- Spirit leveling also called direct leveling. This is the common and precise method used by site engineers.