Laser line level

A laser line level is a tool combining a spirit level and/or pendulum with a laser to indicate a levelled line against a surface. See US Patent 5836081. Invented by Steve Orosz. Handheld laser line levels are used in surveying, construction and cabinetry industries.In surveying, the laser level is affixed to a tripod, levelled and then spun to illuminate a horizontal plane. The laser beam projector employs a rotating head with a mirror for sweeping the laser beam about a vertical axis. If the mirror is not self-leveling, it is provided with visually readable level vials and manually adjustable screws for orienting the projector. A staff carried by the operator is equipped with a moveable sensor which can detect the laser beam and gives a signal when the sensor is in line with the beam (usually an audible beep). The position of the sensor on the graduated staff allows comparison of elevations between different points on the terrain.
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