Leveling In Surveying: Different Types Of Levels
The various devices used for leveling in surveying are known as levels. Dumpy levels, Y levels, Cushing's levels, tilting levels, Cooke's reversible levels, and automated level instruments are some of the kinds of levels used in surveying. In surveying, the technique of measuring vertical distances is known as leveling. To level an item, we'll need some level instruments to concentrate or read it. Nowadays, technology is also used in surveying, and a variety of simple measuring tools have been developed. The numerous levels utilized in leveling are discussed here.
The Different Types of Levels Used in Leveling
The following are the several sorts of levels used in surveying:
The most widely used tool in leveling is the dumpy level. The telescope is prevented from moving in its horizontal plane at this height, and it is locked to its support. On the telescope's top, there is a bubble tube. The leveling head, on the other hand, may be rotated horizontally with the telescope. The internal focusing telescope is a metal tube with four major pieces, which are listed below.
- A lens that is objective
- Negative perspective
Lens that is objective Crown glass and flint glass should be used to make the objective lens. Some faults, such as spherical and chromatic aberration, may be eradicated as a result of this. To decrease the loss due to reflection, the objective lens is coated with a thin layer with a lower refractive index than glass. Negative Perspective The negative lens is positioned parallel to the objective lens. As a result, both lenses have the same optical axis. Diaphragm The diaphragm is installed within the main tube, which has vertical and horizontal cross hairs that are adjustable by capstan headed screws. The cross hairs are comprised of black metal filament wires that are precisely placed into the diaphragm ring. Extra two horizontal cross hairs are supplied above and below the horizontal wire for stadia leveling.
Eyepiece The capacity to sight the object with cross hairs is provided by the eyepiece lens. The picture amplified and reversed via the eye piece. Eyepieces that raise the picture into a normal view are known as erecting eyepieces.
The Y level, also known as the Wye-level, is made up of y-shaped frames that support the telescope. By loosening the clamp screws supplied, the telescope may be removed from the y-shaped supports. These y-shaped frames are attached to a vertical spindle that allows the telescope to rotate. Adjustments may be quickly checked in y- level compared to dumpy level. However, there is a possibility of frictional wear of the level's exposed areas.
In the case of Cushing's level, the telescope is non-removable and cannot rotate in its longitudinal axis. The object and eye piece ends, on the other hand, are interchangeable and reversible.
Level of Tilt
The tilting level is made up of a telescope that allows for horizontal rotation as well as a 4 degree vertical rotation. In this sort of level, centering the bubble is simple. However, with the use of a tilting screw, each setup bubble must be centered. The major benefit of using a tilting level is that it may be used to collect several observations with a single level setup.
Cooke's Reversible Level
Cooke's reversible level is a hybrid of the dumpy and y-levels. The telescope may be rotated without rotating the instrument in this apparatus. Because of the bubble left and bubble right readings of the telescope, collimation error may be reduced in this scenario.
The automatic level is comparable to the dumpy level. The telescope is held in place by its supports in this example. For approximate leveling, a round spirit may be affixed to the side of the telescope. A compensator is installed within the telescope for more precise leveling.
The compensator may assist the instrument in automatically leveling. The compensator, also known as the stabilizer, is made up of two fixed prisms that establish an optical path between the eyepiece and the objective. The compensator causes the optical system to automatically swing into the correct position of line of sight due to gravity's effect. However, before beginning the leveling procedure, the compensator should be examined.
Simply move the foot screws slightly to verify the compensator; if the leveling staff reading stays constant, the compensator is excellent. Tap the telescope lightly to release the compensator if it is not constant. Self-adjusting level is another name for automatic level.