Both laser levels and theodolites are key instruments in the construction and survey industry and since their introduction in the last 50 years they have become the cornerstone for set-out and site levelling in the industry.
Having an understanding of the differences between a laser level and a theodolite is fundamental to all leveling and set-out tasks and construction contractors need to be aware that they designed for different tasks and have quite different capabilities.
In simplistic terms laser levels are simpler to use and more specialised, while a theodolite is more versatile and used on a wider range of tasks.
A laser level projects a laser beam onto a surface directly or via a receiver which picks up the beam to create a perfectly level line or plane.
It is generally used for creating a level or straight line over a relatively short distance and is the instrument of choice for builders, concreters and interior fit-out trades where accuracy and a perfectly level line is required either in a horizontal or vertical plane.
Many advanced laser levels have a slope mode capability that can deviate from a true 0° or 90° line but again this is for the objective of creating a straight line.
From a layman’s point of view think of a laser level as the way to ensure the structure is level and plumb. These are easy to use and quick to set up and are commonly used now by all trades and increasingly by DIYers.
On the other hand, a theodolite is typically used for more complex tasks that require measuring angles and distances in both vertical and horizontal planes and often over longer distances.
It has a telescopic sight that can be angled and rotated to measure angles of a distant object or reference point.
Theodolites are usually used by surveyors, civil contractors, earthmoving contractors, and builders for setting out infrastructure such as roads, earthworks and set out of building foundations and the other structural components that fit around a more complex structure.
Often a theodolite is used in conjunction with GPS receivers or more comprehensive total stations to provide even more precise measurements and data and due to their versatility and the complexity of information and measurements that they can provide they are usually operated by specialists in their respective field.
As always when providing a professional construction service, it is best practice to use high quality reputable brands of instruments and these include iMEX and Topcon for laser levels and Topcon for theodolites.