The tool is leveled according to the accuracy of the device and projects a fixed red or green beam in a plane about the horizontal and/or vertical axis.
[4] A rotary laser level is a more advanced laser level in that it spins the beam of light fast enough to give the effect of a complete 360 degree horizontal or vertical plane, thus illuminating not just a fixed line, but a horizontal plane.
If the mirror is not self-leveling, it is provided with visually readable level vials and manually adjustable screws for orienting the projector.
The position of the sensor on the graduated staff, also known as a grade rod, or story pole, allows comparison of elevations between different points on the terrain.
A tower-mounted laser level is used in combination with a sensor on a wheel tractor-scraper in the process of land laser leveling to bring land (for example, an agricultural field) to near-flatness with a slight grade for drainage.