Construction Laser Levels Explained

When selecting a construction laser, it's not only application specific, there are basically three types of lasers to make your layout less time consuming for certain distances in construction. They are PLUMB ("Dot LASERS"), LINE LEVEL ("Line Generators"), or ROTARY.
For distances from 1' to 150', we recommend PLUMB or LINE GENERATORS. For 200' or greater we recommend ROTARY. These are basic rules of thumb on model selection and things can always vary depending on your exact task or application.

First, lets discuss the basic models. The following levels emit their lasers in various ways

Plumb or Dot Lasers
These lasers produce a single or multiple dot of reference on the wall or work surface. They work much like a reference point, or a laser plumb bob.

Line Level Lasers (Also known as Laser Line Generators)
Another type is one that emits a level line on the wall in a single line, or a cross-hair type of fashion. Typically, these types only emit level lines in one direction and onto a single wall or workspace. These are typically used indoors, and are usually small hand-held types of lasers either positioned on a ladder, saw horse, desk, etc, or mounted to a light-weight jamb-pole or laser platform that extends from floor to ceiling.

Rotary Level Lasers
Then, the other type is a rotary laser, which emits a level line in a rotary fashion. Rotary lasers typically emit a level line around the entire room in 360 degrees. Rotary Lasers are usually a little larger and are mounted on sturdy surveying tripods. Some Rotary Laser Levels can be laid over on their side, using an optional trivet that allows them to project on a vertical plane when used in this manner. The rotation of a single laser makes the human eye think its seeing a line around the room. Hence the name, Rotary Laser. Most all Rotary Lasers work well inside, but if you want to work outside, youll need to make sure you have a laser detector, also known as a laser receiver. This is because the human eye cannot see the laser outside in daylight no more than several feet. More is mentioned below in this article about Laser Detectors.

With the above explanation of how the lasers emit their lines or points, now lets dive into varying types or features of laser levels

Manual-Leveling Lasers
A manual leveling laser requires the operator to manually level the unit by turning the units thumbs screws and getting the unit leveled by looking at the bubble vials.

Self-Leveling and Automatic-Leveling Lasers
A self-leveling laser automatically finds and maintains a level within a specified range. Some lasers have a bubble vial and you perform rough leveling and then the laser itself will take over and do the fine leveling. Or, some you get the laser set up and somewhat close to being level, and then the laser will level itself. And, many self or auto-leveling laser levels will continue to level itself if the setup or platform becomes jarred accidentally. And, many times they will shut themselves off if they get out of level by say 3% or 5% in an attempt to stop you from using the beam as a reference. Also, you should note that some lasers advertise themselves to be Automatic-Leveling. Please be aware that the terms self-leveling and automatic-leveling can mean different things. The terms "self leveling" and "automatic leveling" tend to conflict one another if you're new to laser terminology. Most Self-Leveling Lasers have an internal Pendulum that does the leveling. And some that are called Automatic-Leveling Lasers have electronic servo motors that do all of the leveling for you. We recommend taking the time to read, ask, and learn the differences once you have narrowed down a few lasers when making your decision.

Horizontal Lasers
A horizontal beam laser will only emit a single beam from its beacon.

Dual-Beam Lasers: (also known as Split-Beam Lasers)
These types of laser levels emit horizontal or vertical beams to establish both level and plumb reference lines. Please note that the term of Dual-Beam really just means that the laser is able to produce its regular plane and produce a reference point such as a plumb-up dot on the ceiling. Don't assume that the laser you want will produce a horizontal and vertical "plane" at the same time. Usually when a laser is described as "Dual-Beam", it usually means one level beam like with a Rotary Laser producing a flat line around the room, and the other beam is simply a plumb-up "dot" on the ceiling. We are unaware of any Rotary Laser that will produce both horizontal and vertical level loops around the room at the same time. Most Rotary Lasers are either horizontal, or vertical, (one or the other, not both). Dual-Beam is just another beam, not necessarily another "plane", as the second beam could be a simple "dot" reference point.

Laser Detectors (Laser Receivers)
Also, an integral part of using a Rotary Level Laser is a laser detector. Laser detectors are also known as laser receivers. Laser Detectors typically mount to level rods and work to detect the laser beam when you're working outside. Most always, a laser detector is required if you're working outside with a laser level since a laser line is difficult to see during the daytime hours. Most detectors produce sound, a short beep when you're close to being on level, and then a steady, solid beep tone when you're at level. Laser 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. The visual is usually a LCD screen and the audible is a beeping noise that beeps faster and faster the closer you gets to being on level. When you do get on level, a solid tone that alerts when you're on level. Most detectors will give you a fast tone if you need to move the detector down, a slower tone if you need to move up, and a steady tone when you are on grade

Fixed versus Variable Rotation Speeds of Rotary Lasers
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 in a Rotary Laser 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 (so you get more range). A slower RPM does not travel as far but is brighter and easier to see. 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.

When doing exterior work (outside jobs such as grading, setting culverts, concrete driveways) you need one speed, and that speed is fast. The line from a rotary laser is not visible to the human eye outdoors in bright sunlight, so you will need to use a laser detector to find the exact location of the laser line. The faster the rotation, the harder it is for a human eye to see it, but the laser detectors work better with faster rotations. For a Rotary Laser Detector (Also known as a "Receiver") to locate the line the RPM must be at least 600.

Rotary Laser Levels with variable speeds work well for interior work. A variable RPM allows the user to adjust the laser to the speed of best visibility. Slower rotations have a more visible beam. Faster rotations resemble a chalk line. You’ll want to set the rotation slow enough to where it is just fast enough to be considered a solid line on the wall, as this allows for the best mix of solid and brightness. If you need a solid dot reference set the laser at 0 RPM.

Summary
The laser levels we just discussed are available with varying features. These features may include variable rotation speeds, beam scanning, grade capability, remote controls, rechargeable battery packs, AC chargers and more. Attachments may include a wall/ceiling mount laser platforms, detectors, and trivets for mounting a laser on its side to a tripod for interior work. We recommend you take the time to decide on which jobs or tasks you plan to accomplish while using a laser level. Possibly take the time to write these down on paper, then starting your search. We recommend that you look over the varying comparison charts for Acculine Pro, David White, CST/Berger, Pacific Laser Systems, Sokkia, and Stanley Laser Levels as they can quickly point out which units have which features.

We recommend you take the time to review the varying types of laser level specifications such as the range the laser will emit and accuracy specifications. Working with a construction laser level can save you time and labor while increasing your accuracy. Many setups allow a person to work alone when using a detector on a leveling rod instead of a two-person job with a regular (non-laser) level.

We hope that our document about Construction Laser Levels has helped you learn a bit about them and how they work. And, hopefully you are now off to a good start at selecting the right laser level for you.


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