WATERPASS AND THEODOLITE
WATERPASS
Waterpass is one of the measurement tools used specifically to determine the difference in height between points on the Earth's surface. The reference used is the Mean Sea Level (MSL) or local reference.
Types of Flat Sipats based on their Construction:
- Flat sizing gauge with all parts fixed. Nivo is still placed above the binoculars, while the binoculars can only be rotated with the first axis as a rotating source
- A flat measuring instrument that has a reversal rate and is placed in binoculars. Thus, besides being able to rotate the binoculars with the first axis as the axis of rotation, it can also be rotated with an axis that is in the direction of the aiming line. This rotating axis is called the mechanical axis of the binoculars. The binoculars can be lifted from the bottom of the flatbed gauge.
- Flat measuring instrument with binoculars that have a mechanical axis, but the nivo is not placed on the binoculars, but is placed below, separated from the binoculars. The binoculars can be lifted from the bottom of the flatbed gauge.
- The flat gauge measuring instrument with binoculars can be lifted from the bottom of the flat slide measuring instrument and can be placed at the bottom with a square base, while the nivo is placed on the binoculars.
Image 1. Waterpass Flat Scrub Tool
The parts of the Waterpass are:
- Binoculars are used as sights
- Visir serves as a tool for guiding the shot roughly before being shot through binoculars
- The objective lens is the lens used to capture the object.
- Ocular lens is a lens used to see objects that are located in front of the eye of the viewer.
- Nivo Box serves as a pointer to the I axis in an upright state or not
- Nivo The tube serves as an indicator whether the crosshairs are parallel to the nivo line or not. If the nivo bubble is in the middle forming the letter U, it means that the crosshairs are parallel to the nivo line.
- Diaphragm focuser serves to clarify the state of the diaphragm thread.
- The Shot Focusing Coupler serves to set the target aimed from the binoculars clearly visible
- Three Leveling Couplers function to adjust the nivo bubble or not.
- Setting stakes with a distance of ± 25m.
- Put the WaterPass measuring device at the first point, which is between the front tub and the back tub or yalon one with the other.
- Adjusting the crosshairs to be horizontal, installing the Nivo parallel to the adjusting screw, namely placing the Nivo bubble right in the middle by turning the two adjusters, then the direction of the Nivo line is perpendicular to the axis of rotation. make a horizontal line of the diaphragm perpendicular to the axis of the first axis by the manufacturer.
- Pointing the binoculars at the first tub (or it can be called the back loop), read the top thread, bottom thread and middle thread.
- After that put the direction of the direction on the back in the zero position and then record it.
- Then turn the plane and point it at the front, then also read the top thread, the bottom thread. Also read the angle of direction on the circle of gradation
Theodolit
Theodolite is a tool designed for measuring angles, namely horizontal angles called horizontal angles and vertical angles called vertical angles. Where the angles play a role in determining the horizontal distance and the vertical distance between two field points. In earth surveying work, theodolite is often used in polygon measurements, situation mapping and solar observations. With the binoculars contained in the theodolite, the theodolite can be aimed in all directions. For building works, theodolite is often used to determine right angles in planning / foundation work, it can also be used to measure the height of a multi-storey building.
The main parts that distinguish it from a waterpass are:
- Operating keys are buttons used to give commands on the screen to display angle, slope data, set to 0 degrees, and so on.
- Display is a screen that serves to display the data that has been mentioned in the first point
- An optical plummet telescope is a lens or binoculars that is used to see whether this tool is really on the peg or not. When it is right above it, the peg will be visible from the Optical plummet telescope.
- Horizontal motion clamp is the part used to lock the theodolite's motion horizontally
- The horizontal tangent screw is the part of the Horizontal motion clamp that is used to smoothly move the theodolite in a horizontal direction.
- Horizontal motion clamp is the part used to lock the theodolite's motion vertically or up and down
- The vertical tangent screw is the part of the vertical motion clamp that is used to smoothly move the theodolite in a vertical direction.
- The box nivo is a circle filled with water and air which is used to check the level of flatness on the vertical I axis.
- Nivo tube is a tube filled with water and air which is used to check the level of flatness on the horizontal II axis. Where the horizontal II axis must be perpendicular to the vertical I axis as in gambar 3.
Look at Figures 2 & 3 below:
The parts above will differentiate the function of this instrument so that the scope of work can be wider. One of the weaknesses of this instrument is that it requires a longer tool setting time than the waterpass because it has more complex parts. Before using the Theodolite measuring instrument, care must be taken to keep away metal items that can affect the magnetic needle. The angle of direction obtained is the angle of direction of the magnetic field. How to set up and use the theodolite tool:
- Loosen the extension lock screw
- Raise to chest height
- Tighten the extension locking screw
- Make the legs of the stand in the shape of an equilateral triangle
- Strengthen (step on) the stationary foot pedal
- Adjust the stative height so that the tribar plate is level
- Put the theodolite on the tribar plate
- Tighten the centering locking screw to the theodolite
- Adjust (level) the box level so that the first axis is strictly vertical by moving the flat/flat screw on three sides of the gauge.
- Adjust (level) the level of the tube so that the second axis is completely level by moving the leveling screw on the three sides of the measuring instrument uniformly.
- Position the theodolite by loosening the centering locking screw then sliding it left or right so that it is right in the middle of the fastening point (BM), seen from the optical centering.
- Test the position of the crosshairs with the help of the T mark on the wall.
- Re-check the accuracy of the index value on the circle scale system by reading ordinary angles and extraordinary angles to find out the index error value.
Things to do using theodolite:
1. Horizontal angle reading
- First we release the boussole lock or magnetic fastener, then the reading scale will be seen moving; while moving we wait until the reading scale is silent, then we lock it again.
- The readings are coincidental using a micrometer drum. (Meaning the reading is done on the numbers that differ 1800 or 200gr). The reading of tens of minutes/centi grade and its units is done on the micrometer drum. For ordinary readings, the micrometer drum is on the right. For excellent reading; the drum is on the left. To be able to see the readings under normal or extraordinary conditions, we turn the reading dial (the readings can be rotated either normal/extraordinary with a difference of 1800 or 200gr).
2. Oblique angle reading / direction
- First center the vertical scale bubble using collimator couplers.
- The reading system uses the same number/bottom left as top right. Parts of the scale between the same numbers have units of tens of minutes.
3. Reading signs
- For distance reading, we adjust the upper thread at 1 m or 2 m in meters from the sign. Then read the bottom and middle threads.
- For oblique angle readings, direct the center thread of the binoculars to the height of the instrument, before the reading is carried out, the vertical nivo bubble must be centered first. (tool height must be measured and recorded).
- Read the description.
The theodolite construction is basically divided into 3 parts:
- The lower part consists of a base plate with three adjusting screws supporting an axis tube and a circular horizontal plate. At the edge of this circle is made a limbus lock.
- The middle part, consisting of an axis that is inserted into the tube and placed at the bottom. This axis is the first perpendicular axis. Above the first axis, another circular plate is placed in the shape of a circle having a plate radius at the bottom. In two places on the edge of the circle a nonius reader is made. On top of this nonius plate, 2 legs are placed to support the horizontal axis or the second axis and one tube is placed to make the first axis perpendicular. The circle is made of glass with scale division lines and numbers etched on its surface. The lines are very thin and sharper than the scratches on metal. The circle is divided into sexagesimal degrees, i.e. a full circle is divided into 360° or in centicimal grades, i.e. a full circle is divided into 400 g.
- The upper part consists of a second axis which is placed above the supporting leg of the second axis. On the second axis is placed a binocular which has a diaphragm and thus has an aiming line. On this axis is also placed a plate that is in the form of a vertical circle the same as a circular plate.
Kinds or types of theodolite
Theodolite has various forms. The following are the types of theodolites based on their function and construction:
1. Reiteration theodolite (single axis theodolite)
In this theodolite, the horizontal scale circles become one with the flank, so that the horizontal scale reading cannot be adjusted. The theodolite in question is theodolite type T0 (wild) and type DKM-2A (Kem).
2. Theodolite Repetition
The construction is the opposite of the reiteration theodolite, namely that the horizontal circle can be adjusted and can surround the vertical axis. As a result of this construction, the horizontal scale circle reading 0º, can be determined towards the desired target. Theodolites included in this type are theodolite type TM 6 and TL 60-DP (Sokkisha ), TL 6-DE (Topcon), Th-51 (Zeiss) Oerlee Coolz | Theodolite Oerleebook.wordpress.com | Definition, Terms, types, and types of theodolites.
3. Modern Theodolite
In today's theodolites, reading from both vertical and horizontal circles is usually done electronically. Readout is performed by a rotary encoder, which can be absolute, for example using Gray codes, or incremented, with light and dark equidistant radial bands.
4. Digital theodolite
This type of theodolite is where the horizontal and vertical angle readings are only read automatically on the screen, and the tool is different when the digital theodolite is only done by laser flashing. Examples of digital theodolites: Nikon, Topcon N233, N200, N102.
5. Manual theodolite
The theodolite type where the horizontal and vertical angle readings can only be read manually by looking at the horizontal and vertical reading microscope, but manual theodolites have very small accuracy. Examples of Manual theodolites: Fannel Kessel T0, T1, T11, etc.
