Why Do I need a Laser Level?
A laser diode housed in a pendulum and magnetic self leveller in a dot or line laser and a laser diode housed in a self levelling mechanism in a rotating laser, emit a laser light beam over a defined area that either can be seen or detected by a detector (receiver) at a point level to the laser beam. This then means that everything in the defined diameter from the tool is level.
How Does a Laser Level work?
The main enemy of accurate alignments for laser levels especially over distance is air turbulence. The different temperature gradients between the laser and the target or the receiver causes an effect that is consistent with air turbulence.
It is these temperature gradients that cause “noise” or “jump “in the readings and this is especially exaggerated in high temperatures. Humidity and dust have a small degree of influence; however, this is nowhere near as pronounced as the effect of temperature gradient. The effect is similar to the shimmer seen on a bitumen road on a summers day.
Wind, especially around the unit can also cause complications.
The typical temperature gradient can cause the display to fluctuate by +/- 0.2mm/10m in poor conditions, and these fluctuations are caused by the laser beam going through a number of different temperature gradients which has the effect of bending or refracting the beam before it hits the target. There is no easy solution to overcoming this phenomenon, however there may be a couple of minor tweaks that can be done in certain circumstances to overcome the worst of the condition.
These include keeping the laser and the target protected from wind or air turbulence that may be effect air temperature and the other is not setting the laser up on a hot surface such as bitumen or concrete.
What is the difference between a Dot, Line and Rotating Laser? What is each typically used for?
A dot laser emits only a dot, usually a dot laser has a plumb down, plumb up, and a horizontal dot at 90° to plumb up and down. Sometimes they have 3 horizontal dots at 90°, usually used indoors for partition fit-out, electrical light placement, sprinkler system layout, kitchen & cabinetry set-out and equipment set-up.
Typically used indoors, a line laser emits a line beam, usually one horizontal and a minimum of one vertical – sometimes four at 90°. With a beam of light transmitted to a surface (i.e. a wall) these are highly visible over distances to approximately 10 metres. With a line laser that has a pulse setting to pick up a line detector, these lasers can be used outdoors to 50 metres in some instances. Used for tiling, kitchen or cabinet set-out, electrical drywall setup, partitioning etc. Some indoor lasers can be a combination of a line and dot laser.
A laser with a diode prism that spins at faster speeds, these are typically used indoors or outdoors over longer distances up to 1000 metres diameter, dependant on the size of the laser diode. a detector picks up the beam and is usually mounted on a measuring staff. The rotating laser units mounts on a standard tripod. Some models can be turned on their side and emit a vertical rotating line. Some models allow either manually or automatically, a gradient or slope and some do this in two directions. This allows for an even slope over the entire workplace within the laser working diameter. Used for concreting, excavation, suspended ceiling set-up, landscaping, general building, levelling, earthworks etc. Generally the higher the unit cost, the more added features like gradient, scan, vertical etc. the unit will have.
How Accurate is the Laser?
What is the difference between a green and red beam Laser? Who should buy a green beam?
The frequency of a green beam is such that the human eye can detect it 4 times better that red. A laser with a green diode therefore emits a beam that can be seen over a longer distance, therefore in many instances, does not require the detector and will be seen from the rotating laser as a solid line. This is a big advantage in interior work. Green diodes cost more to produce so usually green diode lasers are about 20% – 25% more costly than an equivalent red beam.
Green beam is the best selection for all round construction, tradesmen who do a mix of interior and exterior work and the best available laser for suspended ceilings and dry walling. Note: a green beam laser is not compatible with a red beam detector. So for earthmoving, where machine control receivers are used, green is not applicable.