Tech Chat | How to quickly center and level the total station?
The total station integrates the functions of angle measurement, distance measurement and height difference measurement, and has three modes of angle measurement, distance measurement and coordinate measurement. It is one of the most practical and functional measuring instruments.
The total station needs to be leveled and centered at a measuring station, so that we can guarantee its accuracy. However, centering and leveling often interfere with each other, and often leveling will affect the result of centering, and centering will affect the result of leveling. So we need to find a fast and efficient method of operation.
The concept of centering and leveling:
Centering and leveling are very basic terms in surveying and mapping discipline. It is the first operation that must be completed by any surveying worker. It consists of two parts: centering and leveling.
- Centering: make the center of the instrument and the center of the test site on the same plumb line. Centering is generally divided into vertical ball centering, optical centering, forced centering and laser centering.
- Leveling: make the vertical axis of the instrument vertical, level plate level.
The purpose of centering and leveling:
- The purpose of centering is to position the instrument so that its center and the site mark are on the same plumb line.
- The purpose of leveling is to adjust the horizontal bubble so that the vertical axis of the instrument is on the plumb line.
Centering and leveling steps:
1. Setting up the tripod
Open the tripod belt, loosen the screws, the tripod opens to a certain angle, adjust the height of the tripod to slightly higher than the shoulder and tighten the screws. The tripod is placed on a known point, and the known point mark on the ground can be seen from the upper round hole through the central bolt. The tripod frame surface is basically level.
2. Attaching the total station on the tripod head
Take the total station out of the instrument box, turn it on, and rotate the leveling screws of the total station to about the middle position, so that the leveling screws have room to rotate clockwise and counterclockwise. Install the instrument on the tripod, note that the circular level should be above one foot of the tripod, and tighten the tribrach fixing lever and the central bolt. Since the tripod is slightly below shoulder level, the instrument should be roughly at eye level.
3. Roughly centering
Turn on the guider laser andgrasp the two legs of the tripod with both hands so that it is half suspended. Using the other leg as a fulcrum, adjust the position of the tripod with both hands until the laser point points to a known point marked on the ground, and gently lower the tripod with both hands. Also, try to make sure the frame surface of the tripod is level.
4. Roughly leveling
① Adjust the tripod legs: Keeping the tripod in the same position, adjust the length of the tripod legs to center the bubble of the circular level for roughly leveling. Since the circular level is above one leg of the tripod, the operator should adjust this leg to control the front and rear position of the bubble, and adjust the other two legs to control the left and right position of the bubble.
② Adjust the leveling screws: Turn the leveling screws A and B to move the bubble in the circular level. The bubble is now located on a line perpendicular to a line running through the centers of the two leveling screws being adjusted. Then turn the leveling screw C to bring the bubble to the center of the circular level.
5. Completely Leveling
Rotate the instrument horizontally by using the Horizontal motion/clamp screw and place the plate level parallel with the line connecting leveling screws A and B, and then bring the bubble to the center of the plate level by turning leveling screws A and B.
Rotate the instrument 90° around its vertical axis and turn the remaining leveling screw or C to center the bubble once more. Repeat this procedures for each 90° rotation of the instrument and check whether the bubble is correctly centered for all four points.
6. Completely centering
After leveling, turn on the guider laser to check whether the total station is still centered. Slide the instrument by loosening the tripod screw, place the point on the center mark, and then tighten the tripod screw. Sliding the instrument carefully not to rotate that allows you to get the least dislocation of the bubble.
Learn more about SingularXYZ total station:
https://www.singularxyz.com/TS1000.html
