What is a laser tool? Where is it applied? How does it work? What is more functional? How to choose the right model? About this right now.
The erection of buildings without the use of measuring instruments is nonsense. However, sometimes, when you make an inspection of an object before drawing up an estimate for repair or reconstruction, it seems that the Soviet “architects” were not familiar with the levels / theodolites, with plumb bows, or with levels. Okay, for state civil construction, you can still find some excuses, but private houses – why is everything so bad? Old school scrapers complain about the lack of racking levels at that time, and when they talk about ancient masters who create perfectly accurate designs using mathematical formulas and simple adaptations, they shrug their shoulders or remember the Leaning Tower of Pisa. In general, the culture of editing has been safely lost, now we start all over again.


Meanwhile, modern construction requires total control literally at all stages, from the layout of the excavation, finishing with gluing of wallpaper and tiling, now everyone dreams that the dwelling was “even and beautiful.” SNiPs and GOSTs of the times of socialism clearly regulate the maximum permissible deviations from the norm, in fact they are no worse than the standards of foreign countries and are quite applicable in the present conditions. But fit into these requirements you need to be able to, or rather want.
In the early nineties we all decided that we want to live no worse than they did and began to make European-quality repairs. The main measuring instrument of masters of a wide profile was the reticular bubble level. Someone now sculpts with their help, and some immediately abandoned this device (at first it was difficult to buy a high-quality device) because of large tolerances, instability of factory settings, a number of functional limitations. The matt finishers took up plumb lines and water levels in the form of transparent hoses, (the gravity of the poor builder is not yet deceiving). At one large facility, the children-subcontractors approach us and ask for a short time the level of “laser level check”. It was a rotational level of Chinese-Polish production with a bunch of problems, but the potential of the device was read with the naked eye.

Laser tool – what is it

This is a measuring instrument, where an ultra-thin, perfectly straight laser beam is used as a marker. This light source is perfectly compacted, focused, split, guided, recognized by auxiliary devices. The point from the laser, even at a distance of several tens of meters, is clearly visible and does not differ in size from the diameter of the outlet in the device, at least their centers coincide. With the help of beam receivers, the range of laser instruments expands to several hundred meters.


The idea of ​​the laser is not new, at the beginning of the twentieth century the impetus to this topic was given by Einstein, in the middle of the last century the military issue was actively engaged in the laser issue, of course, absolutely secretly. Neutral states were quietly engaged in peaceful construction, and in the fortieth year the developers of the Swedish company Spectra Precision applied (and patented) a laser for measuring works. In 1965, they also invented the first laser level, in the 81st – the plane builder was equipped with a light-emitting diode.
In a modern laser instrument, an entire optical system responds to the creation of the beam. Inside the laser LED there are several semiconductors, which generate photons (light particles) under the action of a current. Streams of light, repeatedly reflected from the mirror surfaces of the semiconductor, amplify and exit through a narrow transparent hole. A system of special lenses of various shapes focuses the light and converts it into a line or a thin beam. The laser beam is projected on surfaces to obtain markup (planes, axes, perpendicular lines), or reflected and captured, allowing measurements to be taken. The most important task, which was indicated before the developers of the laser instrument, is its automatic stabilization in the horizontal plane (for the rangefinders it is not so important). The issue of self-leveling was decided in 1974. For this, an independent design of the radiating unit is used, when it (thanks to a simple pendulum and a system of natural or electric magnets acting on it) automatically becomes parallel to the ground. By the way, now there are other options: the alignment of the device can be made both in manual mode (on the bubble – the electronics are fixed in the body rigidly), and completely automatically (servos + gyroscope).

What we get in the result:

  • high accuracy of projection / measurement with an error of tenths of a millimeter on a meter;
  • Instead of a sighting mark (as with traditional levels), we have a visually tangible line or a point where we can “make live” the installation work, start up equipment, etc .;
  • the device is quickly prepared for operation, can be used for instant monitoring as needed;
  • all projection and calculation operations are performed automatically and very quickly, our task is only to deploy it on a more or less horizontal plane;
  • the operator does not require special qualification, the laser tool is successfully used by simple workers and even in everyday life;
  • all operations can be carried out by one person;
  • the productivity of measuring and leveling operations has increased by 40-50%, compared with the use of conventional instruments.


The laser tool, in fact, is an improved analogue of the devices we are familiar with – levels, levels, theodolites, roulettes. What do they do with it? Yes, everything where you need vertical, horizontal or inclined markup:

  • erect / align / position walls and partitions
  • control concrete and earthworks
  • put piles and columns
  • Pipelines, collectors and tunnels
  • mount self-draining gutters and rafters
  • pour screeds
  • fix ceilings
  • set sewage slopes
  • glue tiles and moldings
  • (they are all aware of the effect of the “accordion” of the proflist or siding)
  • hung furniture and heating radiators
  • expose skeletons and door / window blocks
  • collect formwork
  • calculate the area
  • lay communications
  • build right angles
  • simulate curvilinear structures
  • measure distances
  • control the construction equipment (the receiver is mounted directly on the machines)
  • plan plots
  • lay road pavements and curb stone
  • mount fences


Static builders of lines and planes

These are laser devices that are used for marking, as a rule, indoors during construction, finishing and repair work, sometimes on facades and for leveling small areas. Unlike rotary builders, where there is a rotating part, the crossliners are issued constantly directed static lines. They are obtained by splitting a laser beam passing through special optical prisms. Because of the transformation (controlled laser scattering), the visible beam remains at short distances – within 10-20 meters (rarely up to 40), here lies a certain operational limitation. But, using a receiver (this function is not always available), it is possible to mark out planes at a distance of up to 50-100 meters, which depends on the power of the LED and the design features of the particular builder. So the crossliner X-Line Helper 2D has a range up to 40/100 m, and FL 40 pocket II HP – up to 20/60 m (without the receiver / with the receiver).

X-Line Helper 2D
X-Line Helper 2D

Prisms, diodes, rays, and hence the lines can be several, hence the name “multi-prism”. The simplest models (this is a rarity) give one, a vertical or horizontal line. “Standard” devices show two lines intersecting at right angles (a laser cross), for example Condtrol DeuX or BOSCH GLL 2 Professional. The most advanced static builders produce several lines and several crosses, and also emit a point laser up (zenith) or down (nadir), that is, they have a plumb line function. For example, the ADA 6D SERVOLINER (4V4H1D) builds 4 vertical lines and 4 horizontal lines, in addition it gives a pivot point in the nadir.
An important indicator of a static line builder is the angle of development of the rays. The normal figure is about 120 °, the advanced option is 160 or more degrees. A solid level of development allows you to obtain additional crossings of lines (crosses), for example, when the vertical lines cross the zenith point (the crosshair will be “above the head”). Several horizontal and vertical lines can even connect and close in a full plane (all 360 ° are illuminated). The CST / berger LL 20 SET builder shows one full horizon, and the BOSCH GLL 3-80 P draws a record three complete planes (one horizontal and two perpendicular vertical ones), one vertical passing directly through the “facade” of the device, allowing you to hang the plane in the immediate proximity from the ground.

CST berger LL 20 SET
CST berger LL 20 SET

To save the power supply, unnecessary lines can be turned off when performing a specific operation (Makita SK102Z). Usually, they turn off everything except the sheer ray going to the nadir (down).
Almost all modern crossliners have a pendulum or electronic self-leveling system (as an exception – the builder with manual adjustment of Geo-Fennel FL 30). The operator must approximately position the instrument horizontally (for this purpose, a conventional bubble level exists in the design), then the device is installed in parallel for a few seconds using a pendulum compensator or position sensors with servo motors (Condtrol Cube model). During operation, with minor deviations from the horizontal, the self-leveling mechanism adjusts the device, compensating for small movements, vibration. An important indicator is the maximum allowable compensation angle, so the Infiniter CL2 or the Spectra Precision LG20 is self-leveling at angles of deviation up to 5 °, and in general, many devices are satisfied with an indicator of 3-3.5 degrees (VEGA LP90, Leica Lino L360).
If the deviation exceeds the allowable angle of automatic compensation, the device always notifies the operator about it, so that the operator can manually correct the initial position – twist the legs, find the best place. The notification of exceeding the self-leveling range is carried out in different ways: by an audible signal, the indicator blinks on the case, the beam flickers (Makita SK102Z), full device shutdown or combined (Kapro 895 – beeper and beam blinking).
If it is necessary to light a line or a plane at an angle, the compensator can be completely turned off and the device can be built up at its own discretion. This function allows you to save the self-leveling mechanism during standby, during storage and transport (Stabila LAX 200).
Large static builders have adjustable feet for the initial installation and a swivel housing. Those that are more compact are equipped with brackets for fixing the device to the walls, clamps for fixing the crossliner on the pipes, magnetic holders for mounting on metal surfaces (BOSCH GLL 2-50). Each builder can be fastened to a tripod with a 1/4 thread or a professional geodetic tripod with a 5/8 thread. All these adaptations significantly increase the functionality of the instrument.


Axis builders (point lasers)

These are devices that belong to the class of static builders, since in their design there is no rotating radiator. Unlike crossliners, the laser does not build on the surfaces of the lines, here we have only points indicating the direction. What does this give us? Due to the fact that the laser beam does not dissipate through the prism, the point from it is visible at much greater distances than the line, especially in bright sunlight (STABILA LA-4P without a receiver – 30 meters). That is why such devices are well suited for large premises (trade halls, office buildings floors, production halls) or for open spaces. Technically, the dot levels are not much different from the crossliners, here there are all available gadgets:

  • small error level (1-3 mm per 10 meters)
  • self-leveling mechanism (Geo-Fennel Multi-Pointer slope compensation up to 5 °)
  • indication of exceeding the compensator’s capability, position “out of level” (Leica Lino P3)
  • disabling self-leveling (for example, to assemble a stair rail)
  • possibility of fixing on different surfaces
  • application of targets and receivers
Leica Lino P3
Leica Lino P3

Axis builders typically emit three (up / down / forward – Spectra Precision LP30) or five beams (forward / right / left / down / up – Bosch GPL5C). Naturally, all points are projected from the device strictly perpendicular to each other. Spot lasers are used to transfer vertical projections between floors, to determine the direction of partitions, frames, formwork, for building walls, to transfer markup from floor to ceiling …
Since such devices always have rays directed up and down, they are often called laser plummets, although this is only one of the functions. If we put the builder on the floor, we get only the zenith, and if we lift the device on a tripod, we get a nadir, and we can transfer the markup to the ceiling. Some models do not require a special tripod for this, since the radiator is moved forward and raised (Bosch GPL5C).

Bosch GPL5C
Bosch GPL5C

Separate item can be mentioned “almost traditional” laser levels, where the rake with a bubble is supplemented by laser emitters visually extending the measuring line (Geo-Fennel EL 168). To simple laser markers, we refer the builders of point angles. And, of course, there are combined “crossliner / point device” devices, for example Spectra Precision 5.2XL or Condtrol XLiner Combo.

Rotary Laser Level

These devices are designed to determine the direction of construction work, for marking, and, especially, to find the difference in height between points. The laser level, in contrast to the line builder, does not scatter the beam, but forms a vertical or horizontal plane by rotating a light beam – the point pulsates over the surfaces. In fact, this is a point indicator in which the laser rotates around its axis. Thanks to this solution (plus the increased laser power), the developers have achieved a long range of the device, which allows it to be successfully used for leveling operations on large open areas. The leveling of rotary builders is considered to be the most justified (they are several times more expensive than static builders), but they can easily work indoors and when building load-bearing structures. In the makeweight, such a tool can produce a beam going to the zenith (laser plummet for transferring markup to the ceiling), for example, the Spectra Precision HV101.

Spectra Precision HV101
Spectra Precision HV101

Without additional devices, the range of the rotary laser is on the average about 50-70 meters, while with the receiver this distance increases to 300-400 meters (CST / berger ALH – 425 m). The receiver detects the beam in the open area and signals this, after which it is possible to use the scale of the geodetic reiki. It helps to work at great distances, when a person can not see the projection of the beam because of distance, strong sunlight, dust, abundant rainfall. The receiver is usually in the basic configuration, in any case the rotary builder is designed for its use.
Most laser levels have the possibility of stepwise adjustment of the speed of rotation of the radiating head (from 10 to 600 rpm), which greatly extends the functionality of the device, but also allows saving the resource of the power source.
There are rotary builders that show only the horizontal plane, there are those that can be fixed differently on the tripod and automatically aligned vertically or horizontally. The most advanced machines help to create inclined planes. Here either the compensators are completely switched off, or one of the axes is controlled by the device, and the other is manually set.
Some manufacturers are completing their instrument with a remote control (Bosch GRL 300 HV), which contains a full set of buttons available on the body of the level. Therefore, all available manipulations can be carried out at a distance, even from the excavator’s cab or grader.

Bosch GRL 300 HV
Bosch GRL 300 HV

Naturally, rotational levels have a function “beyond the level”, which does not allow making an erroneous markup if there is a serious deviation from the norm. Compensators cope with angles not exceeding 5-6 degrees. During transportation and storage, the self-leveling device is switched off.

Tips for choosing a laser level

We have dealt with the general features and purpose of different classes of laser instruments, now take a look at some “little things” that can limit the functionality of products.
Projection error. If you do not talk about an openly disposable instrument without a name, then this mark will be within 0.5-3 mm by 10 meters. The minimum value (up to 1 millimeter) can be boasted by expensive devices intended for professional use, these are rotary builders (CST / berger ALHV, Geo-Fennel FL 260VA). When buying this point (accuracy) it is worth to check in practice.

Geo-Fennel FL 260VA
Geo-Fennel FL 260VA

Range (visible and scanned range) by famous manufacturers is usually underestimated – in reality everything is better than in passport data. Note that different companies differently indicate the size of the working area (for rotational levels), some speak about the diameter and write 600 meters, others state the radius and write the number “300”. Look, whether the device is suitable for working with the receiver (important for static builders), it is good, if such an option is at least optional.
Laser characteristics – an indicator that directly affects the range of the device. Here we look at its power, class and wavelength. The standard version is a wavelength of 635 nM (red beam with a yellowish tint). Obsolete technology – 650 nM. The best brightness / visibility / comfort / visual range for a green beam with a wave of 532 nM (Spectra Precision HV301G, Geo-Fennel FL 200 and others).
Features of compensation (self-leveling). The limit of automation makes an angle of 5-6 °, and a minimum within 3 degrees is less practical. It is very important here that the compensator be set up quickly (compare this time – it is usually indicated in the passports) and could be switched off (for work with slopes and storage / transportation).
Time of continuous work. Much depends on the type of power source. Static builders are supplied with ordinary finger batteries or batteries and work more than 10 hours. A very useful feature for saving battery is disabling unnecessary lines. Rotary devices require much more energy, so not only alkaline D-batteries, but also NiCd or NiMh batteries (pay attention to the capacity and the speed of the charger). The time of their continuous work reaches 25-40 hours (Leica Roteo 35G). The Topcon RL-H4C builder is 100 hours on one set. And the Bosch GRL 300 HV Professional can operate even from the network. The undoubted advantage of the model will be the presence of a low-charge indication (Spectra Precision LL500).

Topcon RL-H4C
Topcon RL-H4C

Limitation of operating temperature. Agree, it’s not very good if we can not use the device when the temperature is below zero or above 30. Solid professional models of levels operate in the range from -20 to +50 degrees (Stabila LAR200, Spectra Precision LL300-14EU). Determined with this indicator, please note that manufacturers still indicate the acceptable storage temperature – there the range can be wider than the operating temperature.
Degree of protection of the case. As a rule, the user’s manual contains the appropriate marking. The standard version of IP54 will allow you to work on a very dusty area and even under heavy rain. Some developers have achieved more serious successes: IP65, IP67 (CST / berger ALHV). An important point is the protection of the instrument from damages in the fall, the damper plates, the competent ergonomics of the product, the high quality of the materials are very helpful here. A number of manufacturers “allow” to drop their builders from a height of 1 meter or 1.5 meters, if they are fixed on a tripod (Spectra Precision).

CST/berger ALHV
CST/berger ALHV

Equipment. A lot of usefulness of the manufacturers offer in the basic configuration, but something, of course, has to be bought separately. Come on, we just list what the “gentleman’s set” can consist of, and you already orient yourself, what you need and what is not. So:

  • hard case / bag
  • “Red” glasses for laser works (help to see the ray)
  • flat targets
  • remote control
  • radiation receiver
  • Wall / ceiling / magnetic / bracket fastening
  • geodetic rack
  • tripod
  • a set of batteries and batteries, a charger

Anyone who has had experience working with modern laser builders, note only positive moments, indeed, this tool is practically devoid of shortcomings. Even the relatively high cost of such a tool quickly pays off due to the high productivity of marking and leveling works. Well, and, of course, we remember the quality, which, as is known, is priceless.