In this Training Tip blog, our in-house Building Training Manager Zach Francis gives some insight on using a transit level.
How to Use a Transit Level to Find a Level Plane
Once the is set up, leveled, and calibrated correctly, the first step in finding level plane is to find the reference point that was left by the surveyor for the project.
This can sometimes be a nail head in the top of a stake, or a manhole cover, or some other reference point that will be notated on the survey. There is a measurement that is attributed to the height of the reference point, found using a GPS and this will be given to you by the surveyor.
Once you find the reference point, you need to place the bottom of the leveling rod at that point and look through the scope of the transit and write down the distance between the reference point and the plane set by the transit. Once you find that figure, move the level rod to whatever you are looking to measure.
Let’s say you are looking to set final grade. Once you know the difference between the reference point and the level plane set by the transit, you can then subtract the desired finished grade height by the combined distance of the level plane and the distance between the reference point and the level plane.
The elevation of the reference point is 87 feet (Elevation set by surveyor using GPS). You want the finished grade to be at 83.75 feet. The measurement from the reference point to the level plane set by the transit is 4.35 feet. What should the reading be on the Level Rod when it is sitting on the final grade height?
87’ + 4.35’ = 91.35’
91.35’ – 83.75’ = 7.6’
The level rod should read 7.6 feet when it is sitting on the final grade.
Here is a link to a great YouTube video I found that explains this:
Want us to cover a certain topic in our next Training Tips blog? Let us know on social media!