Laser Levels

These basic lasers produce single or multiple dots on the wall or work surface. They work much like a reference point, or a laser plumb bob.

Plumb up and plumb down lasers generate beams that help in framing rooms or transferring measurements from the floor to the ceiling. It also helps in reestablishing a point of reference to the location of a laser level when needed.

These laser levels generate various configurations of lines on a surface. From single line to cross line laser and multiple lines, they can accommodate a variety of needs. Some offer additional features such as plumb up and plumb down, 360° beams, and multiple crosses (when plumb and level lines cross each other).

Rotary laser levels emit a rotating dot at high speed to create a 360° line in the work environment. Rotary lasers come with either a fixed rotation speed, or a variable rotation speed. RPM (Rotations Per Minute) represents the number of times the laser dot rotates in one minute. Most construction rotary lasers have either a fixed RPM or a variable RPM. A faster RPM is dimmer but travels farther, thus achieving a longer range. A slower RPM does not travel as far but is brighter and easier to see. It is recommended to use a slower RPM when inside because the beam will be easier to see, and a faster RPM when outside because it will travel farther. The rotary laser level can act as a solid dot reference by setting the laser at 0 RPM. Usually, the line from a rotary laser is not visible to the human eye when used outdoors or in presence of bright lights. In this case, using a laser detector helps when locating a laser line. For a rotary laser detector to locate the line, the RPM must be set at least at 600.

A laser level detector does not emit, but rather receives the laser beam. Laser detectors are generally used when working outdoors or in bright light where the laser level lines or dots are difficult to see. Laser level detectors can shorten the amount of time needed when trying to find the level beam and get on level. Most detectors have a visual and audible alarm.

A manual leveling laser level requires the operator to manually level the unit by turning a set of knobs and aligning it with fixed level vials that are present on the device.

In self-leveling laser levels, the laser diode is mounted on a pendulum, which allows it to self-level using earth's gravity. The pendulum is usually locked when the laser level is off. The moment the lock is released, the pendulum is set free and can act as a self-leveling mechanism. This feature allows to save time and increases reliability at the job site, especially indoors, where the laser level is moved a lot.

These types of laser levels are more advanced and suitable for higher-end applications. In electronic self-leveling, a set of servo-motors act as the leveling mechanism, which is done automatically based on the current location of the laser level. This method boosts accuracy and reliability, and given the time it takes for initial calibration, is most suitable for outdoors projects where the laser level is set for long period of times.

Laser diodes emit the radiation that creates the beam on a typical laser level. Although laser diodes are compact and have low power requirements (measured in milliwatts), the output they generate is highly visible. There are two types of laser diodes on the market today: red and green.

When shopping for a red or green laser, some specs are worth considering. Green laser beams appear brighter, crisper, and have a slightly increased range. Red lasers have a longer battery life and are a great choice for indoor use. Regardless of laser color, the official recommendation is to use a laser detector when working outside or in an environment that has direct sunlight or bright light conditions.

The color of visible light corresponds to its wavelength (in nanometers) or frequency (in Hertz). Wavelengths that are between 390 to 700 nanometers (nm) are visible to the naked eye, while wavelengths outside this range are not. These waves are within the ultraviolet (UV) or infrared (IR) light. The human eye is the most sensitive to light at a wavelength of about 555 nm. Red lasers’ wavelength is around 635nm (±5nm) and green lasers’ is around 525nm (±5nm). Because the green lasers are closer to the optimum visible eye wavelength it is also more visible.

Laser levels are sensitive to mishandling and can lose or deviate from the initial factory calibration if dropped. It’s generally recommended to check the accuracy of the calibration periodically. The calibration process is done in a manufacturer certified lab and will ensure the declared accuracy of the laser level is restored.

1. Place the laser on a flat surface as close as possible to a long wall.
2. Switch the laser on and press the beam selector button until the horizontal beam is projected.
3. Make two marks on the wall at the laser line – one close to the laser and one as far away as possible.
4. Move the laser unit as close as possible to the second mark.
5. Measure the height difference between the laser line and the two points previously marked on the wall.
6. If the height differences at the two pints measured are identical, the laser level is horizontally calibrated.

1. Hang a plumb line from a high point on a wall.
2. Place the laser on a flat and steady surface about 1m (3ft) from the wall.
3. Press the Beam Selector button until the vertical beam is projected.
4. Adjust the laser line so it converges with the bottom of the plumb line.
5. If the laser line is converging with the plumb line at the top, the laser is calibrated.

Accuracy represents the degree of deviation or tolerance of the output laser beam at a given range. Professional laser levels have various degrees of tolerance, ranging from 0.1mm/m - 0.4mm/m (0.0001In/In - 0.0004In/In). This means that at the higher tolerance end, a laser level can deviate up to 0.1 mm at a range of 1 meter (or 0.0001 Inch at 1 Inch away).

The laser level range refers to the visibility of the laser beam from the laser level device to the farthest point of reach. The range will vary if the laser level is used indoors or outdoors as ambient light conditions might affect it. When using a laser level outdoors, it’s recommended to also use a detector.

The self-leveling range is the scope of variation within which the pendulum stays level as measured in degrees. The greater the range, the more capable the laser level to compensate for surface deviation. Professional laser levels will offer self-leveling capability of at least ±3°.

To use a detector to indicate a laser beam's location, a laser must be in pulse mode. In pulse mode, the laser level changes the way the beam is projected; from continuous line to pulse of dots. This change is hardly visible to the naked eye but allows the detector to read the laser beam as needed.

The durability of any laser level depends on its casing, and how securely fastened the self-leveling mechanism and diode is. A shock resistant rubber casing is a must for a laser level that contains sensitive internal parts and is placed in the toughest work environments.

The higher the classification of a laser, the more dangerous the beam isto the human eye when in direct contact. Class II lasers are considered safe and are commonly used due to the output being less than 1mW. This makes a laser still powerful enough to accommodate day to day needs, without significant risk to eye damage.

The IP rating denotes the degree of protection provided dust and water to mechanical casings and electrical enclosures. It is comprised of two digits:
1. The first digit stands for solid particle protection (dust) - Grade 6 is the highest grade of dust resistance and is extremely useful when working drywall projects or in dusty environments.
2. The second digit of the IP code stands for liquid ingress protection (water) - Grade 5 covers dripping, rain and splashing water which is suited for an indoor or outdoor construction work environment.