What is a Laser?
An atom, in the simplest model, consists of a nucleus and orbiting electrons. This simple atom consists of a nucleus (containing the protons and neutrons) and an electron cloud. It’s helpful to think of the electrons in this cloud circling the nucleus in many different orbits.
The Laser/Atom Connection
A laser is a device that controls the way that energized atoms release photons. "Laser" is an acronym for light amplification by stimulated emission of radiation, which describes how a laser works.
Lasers are classified into four broad areas depending on the potential for causing biological damage. When you see a laser, it should be labeled with one of these four class designations:
• Class I - These lasers cannot emit laser radiation at known hazard levels.
• Class I.A. - This is a special designation that applies only to lasers that are "not intended for viewing," such as a supermarket laser scanner. The upper power limit of Class I.A. is 4.0 mW.
• Class II - These are low-power visible lasers that emit above Class I levels but at a radiant power not above 1 mW. The concept is that the human aversion reaction to bright light will protect a person.
• Class IIIA - These are intermediate-power lasers (cw: 1-5 mW), which are hazardous only for intrabeam viewing. Most pen-like pointing lasers are in this class.
• Class IIIB - These are moderate-power lasers.
• Class IV - These are high-power lasers (cw: 500 mW, pulsed: 10 J/cm2 or the diffuse reflection limit), which are hazardous to view under any condition (directly or diffusely scattered), and are a potential fire hazard and a skin hazard. Significant controls are required of Class IV laser facilities.
About Construction Lasers
There are three basic types of beam correction for construction lasers. They are divided by the way they level beam.
1.) The first is the most simple; it is a laser diode that is leveled by an external leveling vial that the operator adjusts with external leveling screws. You can identify this one by external leveling screws and when shaken lightly you should hear nothing.
2.) The second is leveled with a compensator. A compensated laser works like a laser diode attached to a hanging plumb bob. This one is can be identified by lightly shaking the laser and listening for some kind of a rattle inside that will be the compensator. It will have leveling screws on outside of laser for the operator to adjust.
3.) The third is fully automatic in the leveling process. It has electronic leveling vials that monitor the laser diode and make any adjustments to make and keep the beam level. This type will have no leveling screws on the outside. Therefore the operator will not have the means or the need to adjust for level. This is the easiest and most consistent laser to use.
Construction Laser Setup and Operation
1.) Setup your tripod as level as possible, step on tripod legs to drive into the ground.
2.) Attach your laser to the tripod and turn on laser. If needed adjust leveling screws to get unit as level as possible.
3.) Calibration should be checked before the start of the day. This is done by picking a spot (a wall, tree or stake in the ground) around 50 feet away.
With the keypad facing you move laser to face the wall, tree or stake. Go to the wall with detector set to the finest mode move detector up thru the beam until you get on center beam on the detector.
Draw a mark across the top of detector on the wall. Go back to laser and turn 180 degrees. Go back to the wall move detector up thru beam to on center of beam and Draw a mark across the top of detector on the wall.
Go back to the laser and turn unit 90 degrees from where it is sitting now.
Move back to the wall and move detector up to center on beam draw a line across top of detector again. All marks should fall on top of each other.
Go back to laser and turn 180 degrees. Move back to wall move detector up to center of beam and make a forth mark on wall. All marks should fall on top of each other if not the error needs to be corrected by a competent repair technician.