Video: How to Establish Grade with an Electronic Self-Leveling Laser

Johnson Level demonstrates using the 40-6537 electronic self-leveling rotary laser level on a construction jobsite for establishing a grade from either a known point of elevation or the height of the instrument. Finding elevations is important to grading, excavation and building up.

VIDEO SCRIPT

Hello my name is Dave Statza and I'm with Johnson Level & Tool. Today, we're demonstrating the outdoor applications for the Johnson 40-6537 electronic self-leveling rotary laser level.

When using the rotary laser outside, its important that you have a tripod to have you laser sit on, a grade rod and a detector or receiver. This is what will actually see, or detect, the laser beam in outdoor applications. Once the 40-6537 is mounted onto the tripod, simply power on the laser. The laser level will electronically self-level itself, and once level, will begin to rotate.

Typically on a job site there's a known point of elevation called a benchmark. And that's an elevation that is brought out by a surveyor. But if there's not a known point of elevation on a job site, you can establish your own benchmark just by going to the same reference point and determining what the height of your instrument is.

Now my laser level detector sees the laser beam and tells me if I need to take the detector and move it up or move it down to be at the same grade as the laser beam. A down signal, signals to me that I need to move down; an up signal tells me that I need to move up. And when I have a steady tone, that means that my laser detector is now level with my laser beam.

So knowing that my laser level now is setup at 4 feet 5 and 3/4 inches, I now can determine any elevation on the job site [moves to a new location and uses the laser detector to find the elevation of the laser level]. And I now have a new elevation of 3 feet, 1 inch.

By knowing the different elevations between my benchmark and my new point, I now know that I am approximately 2 feet higher in this position than I was at my benchmark. Which is important for grading purposes, to make sure the water runs away from the house. So you need to know the different elevations from your benchmark and from your different points on a job site because all job sites have different terrains and different elevations. For whether you're digging a basement, or digging footers, or adding dirt to create slope for water flow away from the house, that's why its important to know what these different elevations are for.