ABOUT: ELECTRONIC LASER LEVELS, also called Rotary or Construction Lasers, cast a horizontal plane of light. Light from infrared lasers (IR) cannot be seen and a handheld detector must be used to find the signal. Even bright visible beam lasers usually require a detector when used outside in direct sunlight. Some ELECTRONIC LEVELS must be manually leveled and others use a servo-motor system to electronically level the laser.
Most electronically leveled lasers have an instrument height (HI) alert so if the unit moves the laser won't re-level at a different instrument height. Lasers that use a mechanical compensating system shut the laser beam off if the unit shifts. Units that have no mechanical or electronic system must be carefully watched after initial leveling because a laser plane will continue to be broadcast even if the laser changes elevation or position.
Most ELECTRONIC LEVELS can use either alkaline or rechargeable batteries. Accuracy is usually indicated by how far the laser plane can be off "dead level" in 100 feet, either above or below the "dead level" plane. Some unit accuracies are indicated in arc seconds ("). 10" indicates an accuracy error of 1/16" @100'.
Various degrees of "waterproofness" are found in the family of ELECTRONIC LEVELS. For the specific level of "waterproofness", refer to the IP Ingress Protection Code and IPX Degree of Protection specifications for the individual laser. Most moisture damage happens when a wet instrument is put away in its case. HINT: Always let a wet instrument air out by placing in a dry, warm environment after having gotten wet. As important, dry out the case so moisture won't be trapped inside.
Many variations can be found in ELECTRONIC LEVELS. Some can allow tilting the plane of light to accompish rough slope work and others can emit a beam at 90 degrees to use for layout. Some ELECTRONIC LEVELS have a fixed rotational speed (often 600 rpm), but others have variable speeds.