Laser Line Levels

Today, the three most common types of laser levels are Rotary Laser Levels, Laser Line Levels (or Line Generators) and Dot Laser Levels (or Multi-Point Lasers) This article focuses on the technical specifications of Laser Line Levels.

Laser Line Level

electrician placing a wall switch with Johnson Self-Leveling Ultra-Bright Cross-Line Laser Level Model: 40-6625 Line Laser Levels project a beam of light typically 180-degrees both horizontally and vertically, allowing the user to establish a horizontal or vertical plane. Some Laser Line Levels can also project a beam of light 360-degrees. In fact, this beam of light is really a single dot of light that when projected through a beam spreading prism, projects a 180 or 360-degree chalk line. When working indoors, the Line Laser Level is useful for anything needing horizontal leveling around a room or a vertical leveling from floor to ceiling.

The beam of light is created by what is called a diode, which in this case is simply a semiconductor which produces light when current passes through it. We see diodes everyday on our CD players, computers and television remote controls.

Line Laser Leveling Method

Laser Line levels are leveled in two ways. The first is manual leveling, which means you the operator make the laser level by adjusting the laser to bubble vials built into the laser. Accuracy is going to depend on the quality of the level vial and the operator's eye. Although accuracy can be 1/2" per 20 feet and setup is longer due to the manual leveling, it is the least expensive laser available. The second method to level a rotary laser is Self-Leveling, which means the laser levels itself through a pendulum and magnets. Accuracy is typically 1/8th inch per 50 feet, better than manual

Color - Laser Level Wavelength

Color is technically determined by the wavelength of the laser (the laser diode actually), which is measured in nanometers (nm), one billionth of a meter, because of its very small length The spectrum of color visible to the human eye is between 380 nm (purple) and 750 nm (red) Typically, the color of the laser is red (635 nm) or green (532 nm and near the center of the spectrum, making it the most visible to the human eye). Johnson Level's green-beam laser system, called GreenBrite Technology, is at least 400% brighter and more visible than a red laser. Regardless of the color, you will not be able to see the light from the Line Laser Level outside, you always need a Laser Detector in daylight.

Intensity - Laser Level Classification

The intensity of the laser is determined by the level of laser light power which is measured in milliwatts (mw), 0.001 or one-thousandth of a watt Class I and II lasers are low power from below 0.4 mw to 1 mw Typically, laser levels are Class IIIA, which is between 1 mw and 5 mw At these levels, the laser is safe if it catches your eye, although you should not stare at it The nearer your laser is to 5 mw, the brighter it is, and also the more expensive Since Class IIIB lasers which range from 5 mw to 500 mw and require controls, and Class IV lasers are high power lasers above 500 mw, which are hazardous to view under any condition, they are typically not used for leveling tools.

Laser Level Accuracy

Accuracy of a line laser level ranges from +/- ½" to +/- 1/8" 50 feet Although this accuracy is greater than a spirit level (or bubble level), a spirit level cannot give you the distance a laser level can.

Laser Levels Working Range

How far the line laser goes is typically specified in terms of feet in diameter. Since the Line Laser Level is the center of the range, the distance in any one direction is the radius, or one-half the diameter specified. The range can be up to 300 feet in diameter with a detector (most likely used outside due to the distance and inability to see the laser outside). If you're inside and can see the laser beam.

Now that you are familiar with the technical specifications of a Line Laser Level, you are now ready to understand how Laser Line Levels are used by contractors.