A rotary laser level is a device that indicates horizontal or vertical levels or other construction points by means of a continuous, 360 degree arc of laser light. This continuous line of light is projected onto walls, floors, or other structures to facilitate the marking of construction levels or to align different components that are mounted at a common height. The rotary laser level differs from conventional laser levels in that it projects the laser reference in a 360 degree arc. This can be used to project the reference line on all walls or the floor and ceiling of a space simultaneously as opposed to a single line plane.
The rotary laser level is used predominantly in the commercial construction industry as it allows for level references to be projected on all interior surfaces at once. This laser reference may be projected horizontally, vertically, or at any preset angle. Although the rotary laser level would also be useful in the do-it-yourself, or DIY, field, the size and cost of the units prohibits general purpose home use. The standard single reference laser level is far more appropriate for DIY use.
Another benefit of using a laser level is the fact that the reference line always stays on top of the working surface, thereby making layered construction easier. Rotary laser levels give the added benefit of the 360 degree projection arc which can cover an entire internal area from one projection point. This makes marking out bracing, paneling, or any construction element that runs around more than one wall of a room far easier than using any conventional level. This functionality extends to both spatial planes and adds considerable flexibility and very high levels of accuracy to construction measurement.
A rotary laser level should ideally be used from a laser level tripod but any stable and fairly level surface will suffice. Most units are self leveling so setting them up is not difficult. A typical device also incorporates warning features that flag the user if the unit moves or goes out of level during operation. Rotary laser level units are available in standard red diode models and new high visibility green light variants which are far more visible in bright light conditions.
The only real downside of the rotary laser level is the fact that the device tends to be far more expensive than static laser levels. Unfortunately, this makes buying one difficult to justify for DIY enthusiasts. It can be, however, indispensable hardware in any construction team's arsenal, offering far superior results than static laser levels and other conventional level reference methods.